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Virginia SOL Mathematics Textbook

Algebra 1 Workbook — Chapter 3: Linear Inequalities in One Variable

SOL A.EI.1 (c, f) · Companion to Textbook Chapter 3

Each page below is one Canva page. Headings are sized for direct paste: page title as H1, section labels as H2. Figures referenced by filename live in ../figures/. Every numbered item is the same problem as in the textbook, so one answer key serves both. Item numbers run continuously from 1 to 88.


PAGE 1 — Chapter opener

Chapter 3 · Linear Inequalities in One Variable

Standard A.EI.1 (c, f)

In this chapter you will:

Words to know: inequality · strict · inclusive · solution set · boundary value · properties of inequality · distributive property · like terms · coefficient · reciprocal · reversal rule · reflection · open circle · closed circle · ray · verify · interpret in context

Reminder: reverse the symbol only when you multiply or divide both sides by a negative number.


PAGE 2 — What an inequality asks

3.1 A Point, or a Region?

FIGURE: fig1-equation-versus-inequality.png (full width)

FIGURE: fig2-open-versus-closed.png (full width)

Fill in the blanks.

The symbols << and >> are called ____________ inequalities, and the boundary number ____ a solution.

The symbols \le and \ge are called ____________ inequalities, and the boundary number ____ a solution.

Open circle for the symbols ______ and ______. Closed circle for ______ and ______.

Shade ____________ for >> or \ge. Shade ____________ for << or \le.

Guided practice.

  1. Is x=2x = -2 a solution of 4x+73x+54x + 7 \le 3x + 5?

    Left side: 4()+7=4(\underline{\hspace{1cm}}) + 7 = ______ Right side: 3()+5=3(\underline{\hspace{1cm}}) + 5 = ______

    Number sentence: _______________ True or false? ______ Solution? ______


PAGE 3 — Guided practice, Lesson 3.1

Naming Every Step

  1. Solve and graph 3x5<73x - 5 < 7.

    Solution: _______________ Endpoint: ______ Circle: open / closed Shading: left / right

  2. Solve 2x+172x + 1 \ge 7. Name the property beside each line.

Line Property used

Solution: _______________

  1. Solve 5x3>2x+95x - 3 > 2x + 9, naming the property at each step.
Line Property used

Solution: _______________ Boundary test, x=4x = 4: ______ True / false: ______


PAGE 4 — Graphing frames, Lesson 3.1

Graph These

FIGURE: fig8-blank-number-lines.png (full width)

Use line a) for item 2 and line b) for item 3. Lines c) and d) are for items 5a and 5b; reprint the frame for 5c and 5d.

  1. Solve and graph.
a) x+610x + 6 \le 10 b) 7x>217x > 21
c) 4x9114x - 9 \ge 11 d) 13x+2<5\dfrac{1}{3}x + 2 < 5
  1. 6x+54x+176x + 5 \le 4x + 17 Solution: _______________ Property used to move the 4x4x: _______________

  2. Rewrite 15<5x15 < 5x with the variable first: _______________ Then graph it.


PAGE 5 — Independent practice, Lesson 3.1

Practice · Sets and Sentences

  1. Which values from 5-5, 00, 2.52.5, 44, and 99 are solutions of 3x4x+63x - 4 \le x + 6?

    Solved form: ____________ Solutions: _______________

  2. A number line shows a closed circle at 2-2 with shading to the right.

    Inequality: _______________

    A multistep inequality with the same solution set: _______________

    Show that it does: _______________________________________________

  3. Name three solutions of 2x+9>32x + 9 > 3, including one negative and one that is not an integer.

    ______ ______ ______ Show one check: _______________________________________________


PAGE 6 — Application and reasoning, Lesson 3.1

Apply It · Explain It

  1. Apply it. A robotics club has $120\$120. A base kit costs $45\$45, and each sensor costs $5\$5.

    Let s=s = _______________________________________________

    Inequality: _______________ Solution: _______________

    Greatest whole number of sensors: ______ Check at that value: _______________

  2. Explain. Why is the answer to 2x+1=72x + 1 = 7 a single point, while the answer to 2x+172x + 1 \ge 7 is a ray?


    Where does the number 3 come from in both problems? _______________________________________________


PAGE 7 — Exit ticket 3.1

Exit Ticket · Lesson 3.1

Name: ________________________ Date: ____________

  1. 5x8<25x - 8 < 2 Solution: _______________ Circle: open / closed Shading: left / right

  2. Is x=3x = 3 a solution of 4x52x+14x - 5 \ge 2x + 1?

    Left: ______ Right: ______ True or false? ______ Solution? ______

  3. 8x+35x+188x + 3 \ge 5x + 18 Solution: _______________

  4. State the open-circle and closed-circle rule, and say why the rule is what it is.



PAGE 8 — Why the symbol reverses

3.2 The Reversal Rule

FIGURE: fig3-reversal-reflection.png (full width)

FIGURE: fig4-slide-versus-reflect.png (full width)

Complete each sentence.

Multiplying both sides by a negative number ____________ every point across zero, so the order ____________.

Adding a negative number ____________ both points the same distance, so the order ____________.

Guided practice.

  1. Start with 2<52 < 5. Multiply both sides by 3-3.

    Left: ______ Right: ______ True statement: _______________ Direction changed? ______

  2. Start with 2<52 < 5. Add 8-8 to both sides.

    Left: ______ Right: ______ True statement: _______________ Direction changed? ______


PAGE 9 — Guided practice, Lesson 3.2

Reverse, or Leave It Alone?

FIGURE: fig5-solve-and-graph-reversal.png (full width)

  1. Solve and graph 3x+722-3x + 7 \ge 22.

    Solution: _______________

    The direction reverses at this step: _______________________________________________

  2. Solve 25x<6-\dfrac{2}{5}x < 6. Solution: _______________

    Boundary test, x=x = ______ : ______ Inside test, x=x = ______ : ______


PAGE 10 — Independent practice, Lesson 3.2

Practice · Reverse or Not?

  1. Solve and graph.
a) 5x>20-5x > 20 b) x+310-x + 3 \le 10
c) 12x41-\dfrac{1}{2}x - 4 \ge 1 d) 83x<238 - 3x < 23
  1. Solve both. Only one reverses.

    a) x83x - 8 \ge -3: _______________ b) 8x3-8x \ge -3: _______________

    Why only one? _______________________________________________

  2. 62(x+4)>106 - 2(x + 4) > 10 Solution: _______________

  3. 47x3x264 - 7x \le 3x - 26 Solution: _______________ Boundary check: _______________

  4. Does the direction reverse? Circle one and give the reason.

Move Reverses? Reason
a) subtract 5x5x from both sides yes / no
b) multiply both sides by 34-\tfrac{3}{4} yes / no
c) distribute 2-2 across (x3)(x - 3) yes / no
d) divide both sides by 0.50.5 yes / no

PAGE 11 — Application and error hunt, Lesson 3.2

Apply It · Find the Error

  1. Apply it. A drone hovers at 320 feet and descends 25 feet per second, so its altitude after tt seconds is 32025t320 - 25t feet.

    Inequality for "below 145 feet": _______________

    Solution: _______________

    Sentence answer: _______________________________________________

  2. Explain. Start with 8<2-8 < -2 and multiply both sides by 12-\tfrac{1}{2}.

    True statement: _______________

    Why did the direction have to reverse? _______________________________________________

  3. Find the error. Kai solves 5x+2>17-5x + 2 > 17, reaches 5x>15-5x > 15, and writes x>3x > -3.

    Test x=0x = 0 in the original: ______ True or false? ______

    What went wrong? _______________________________________________

    Correct solution: _______________


PAGE 12 — Exit ticket 3.2

Exit Ticket · Lesson 3.2

Name: ________________________ Date: ____________

  1. 4x+511-4x + 5 \le -11 Solution: _______________ Circle: open / closed Shading: left / right

  2. 10x3>1210 - \dfrac{x}{3} > 12 Solution: _______________

  3. Start with 9<6-9 < 6 and divide both sides by 3-3. True statement: _______________

  4. Why does multiplying both sides by a negative number reverse the symbol, while distributing a negative number does not?



PAGE 13 — Multistep work

3.3 Clean Up, Collect, Isolate

The order of work.

  1. ____________ every product written with parentheses.
  2. ____________ like terms on each side.
  3. ____________ the variable on one side.
  4. Move the ____________ to the other side.
  5. Divide by the ____________, and ask the reversal question.

Distribute carefully. The outside factor multiplies every term inside, keeping its sign.

3(x+2)=-3(x + 2) = \underline{\hspace{2cm}} 2(x+6)=-2(x + 6) = \underline{\hspace{2cm}} 4(x3)=-4(x - 3) = \underline{\hspace{2cm}}

Guided practice.

  1. 3(2x5)+4253(2x - 5) + 4 \le 25
Line Property used
Solution: _______________
  1. 5x2(x+6)>35x - 2(x + 6) > 3 Solution: _______________ Boundary check, x=5x = 5: _______________

PAGE 14 — Guided practice, Lesson 3.3

Two Routes, One Answer

  1. Solve 7x+410x117x + 4 \ge 10x - 11 two ways.
Subtract 7x7x first Subtract 10x10x first
Same answer? ______   Which route reversed? ____________   Why? ____________________
  1. Solve and graph 2(3x)4(x+3)62(3 - x) \ge 4(x + 3) - 6.

    Solution: _______________ Endpoint: ______ Circle: open / closed Shading: left / right


PAGE 15 — Independent practice, Lesson 3.3

Practice · Expand, Combine, Solve

  1. Solve and graph.
a) 4(x3)<84(x - 3) < 8 b) 2(x+5)4-2(x + 5) \ge 4
c) 6x3(x2)186x - 3(x - 2) \le 18 d) 23(9x6)>20\dfrac{2}{3}(9x - 6) > 20
  1. 85(2x1)178 - 5(2x - 1) \ge -17 Solution: _______________ Property at the reversal step: _______________

  2. 9x4<5x+129x - 4 < 5x + 12 Solution: _______________

  3. 0.4x+1.20.9x0.80.4x + 1.2 \ge 0.9x - 0.8 Solution: _______________

  4. 3(x+2)4x2(4x)3(x + 2) - 4x \le 2(4 - x) Solution: _______________


PAGE 16 — Error hunt, application, reasoning, Lesson 3.3

Find the Error · Apply It · Explain It

  1. Find the error. Dana solves 4(x3)20-4(x - 3) \le 20 by writing 4x1220-4x - 12 \le 20.

    What went wrong? _______________________________________________

    Correct solution: _______________ Dana's answer: _______________

    Test x=3x = -3 in the original: ______ Is 3-3 in Dana's set? ______

  2. Apply it. Hall A charges $250\$250 plus $22\$22 per guest. Hall B charges $400\$400 plus $16\$16 per guest.

    Let g=g = _______________________________________________

    Inequality for "A costs no more than B": _______________ Solution: _______________

    What it means: _______________________________________________

  3. Explain. Solve 73(x2)4x87 - 3(x - 2) \ge 4x - 8: _______________

    Two places a sign could go wrong here: _______________________________________________


PAGE 17 — Exit ticket 3.3

Exit Ticket · Lesson 3.3

Name: ________________________ Date: ____________

  1. 6(x1)+2206(x - 1) + 2 \le 20 Solution: _______________

  2. 124(x+1)>2x412 - 4(x + 1) > 2x - 4 Solution: _______________ Circle: open / closed Shading: left / right

  3. 5x79x+55x - 7 \ge 9x + 5 Solution: _______________

  4. Why can expanding and combining like terms never reverse the symbol, even when the factor is negative?



PAGE 18 — Three ways to be sure

3.4 Verify · Explain · Interpret

FIGURE: fig6-graphical-verification.png (half width, right)

The three verifications.

Algebraically: substitute into the ____________ inequality — one value ____________ the set, the ____________ itself, and one value ____________ it.

Graphically: graph each side as a line. They cross at the ____________. The solution set is where the correct line is ____________.

With technology: enter the two sides as Y1Y_1 and Y2Y_2, use ____________ to find the boundary, then read the ____________ to decide the direction.

Guided practice.

  1. Verify that 4x72x+14x - 7 \ge 2x + 1 solves to x4x \ge 4.

    Inside, x=x = ______ : ______ Boundary, x=4x = 4: ______ Outside, x=x = ______ : ______

  2. Verify graphically that 2x1>x+12x - 1 > x + 1 solves to x>2x > 2.

    The lines cross at ( ______ , ______ ). Higher to the right of the crossing: _______________

    Why is the crossing point excluded? _______________________________________________


PAGE 19 — Technology and context, Lesson 3.4

Calculator Check · Say What It Means

FIGURE: fig7-context-whole-tables.png (full width)

  1. Verify 3x+722-3x + 7 \ge 22 with a graphing calculator.

    Y1=Y_1 = ____________ Y2=Y_2 = ____________ Intersection: ( ______ , ______ )

    Which side of the crossing is Y1Y_1 higher? ____________ Solution: _______________

    What the table row at the boundary shows: _______________________________________________

  2. Apply it. A student council has $500\$500. The DJ costs $180\$180 and decorations cost $12\$12 per table.

    Let t=t = _______________________________________________

    Inequality: _______________ Solution: _______________

    Test t=26t = 26: ______ Test t=27t = 27: ______ Whole tables: ______


PAGE 20 — Independent practice, Lesson 3.4

Practice · Verify Three Ways

  1. 3x+25x83x + 2 \le 5x - 8 Solution: _______________

    Inside, x=x = ______ : ______ Boundary: ______ Outside, x=x = ______ : ______

  2. 2x+9>1-2x + 9 > 1 Solution: _______________

    The lines y=2x+9y = -2x + 9 and y=1y = 1 cross at ( ______ , ______ ). Higher to the left: ____________

  3. Use the table to decide where 52xx45 - 2x \ge x - 4.

xx 0 1 2 3 4 5
Y1=52xY_1 = 5 - 2x 5 3 1 1-1 3-3 5-5
Y2=x4Y_2 = x - 4 4-4 3-3 2-2 1-1 0 1
From the table: _______________   Solved algebraically: _______________   Do they agree? ______

PAGE 21 — Application and interpretation, Lesson 3.4

Apply It · Say What It Means

  1. Apply it. A phone plan costs $35\$35 per month plus $0.05\$0.05 per extra text. Amara will spend at most $50\$50.

    Inequality: _______________ Solution: _______________ What it means: ____________________

  2. Apply it. An elevator carries at most 2{,}000 pounds. The operator weighs 180 pounds; crates weigh 65 pounds each.

    Inequality: _______________ Solution: _______________

    Why is the endpoint usable here? _______________________________________________

  3. Interpretation. A subscription problem gives m13.75m \le 13.75, where mm counts whole months.

    In a sentence: _______________________________________________

    Greatest usable value: ______ Check at that value: ______ Check at the next one: ______


PAGE 22 — Reasoning and error hunt, Lesson 3.4

Explain It · Find the Error

  1. Explain. Why is one inside test not enough to verify a solution set?


    The three tests that are convincing: ____________ , ____________ , ____________

    Which one decides open versus closed? ____________

  2. Find the error. Priya solves 62x146 - 2x \ge 14 and reports x4x \ge -4.

    Test x=0x = 0 in the original: ______ True or false? ______

    What went wrong? _______________________________________________

    Correct solution: _______________ Correct graph: _______________________________________________


PAGE 23 — Exit ticket 3.4

Exit Ticket · Lesson 3.4

Name: ________________________ Date: ____________

  1. 43x<194 - 3x < 19 Solution: _______________

    Inside: ______ Boundary: ______ Outside: ______

  2. To check item 61 graphically, graph Y1=Y_1 = ____________ and Y2=Y_2 = ____________ .

    They cross at ( ______ , ______ ). Which side is Y1Y_1 lower? ____________

  3. Apply it. A food truck charges $2.75\$2.75 per taco plus a $3.00\$3.00 packaging fee. Devon has $25.00\$25.00.

    Inequality: _______________ Solution: _______________ Tacos: ______

  4. What does it mean to interpret a solution in context? Give an example where the algebraic endpoint is not the practical answer.



PAGE 24 — Chapter 3 review, part 1

Chapter 3 Review

Part A · Solving and graphing (A.EI.1c)

  1. Solve and graph. State the endpoint, circle type, and direction.
Solution Endpoint Circle Direction
a) 5x3125x - 3 \ge 12
b) 2x+11<32x + 11 < 3
c) 6x18-6x \le 18
d) x41>2\dfrac{x}{4} - 1 > 2
  1. 4(x2)+9174(x - 2) + 9 \le 17 Solution: _______________
Line Property used
  1. 72(x+3)>57 - 2(x + 3) > 5 Solution: _______________

PAGE 25 — Chapter 3 review, part 2

Chapter 3 Review (continued)

  1. 8x+13x148x + 1 \ge 3x - 14 Solution: _______________

  2. 34x+2<1-\dfrac{3}{4}x + 2 < -1 Solution: _______________

  3. 5(2x3)3(3x+1)5(2x - 3) \le 3(3x + 1) Solution: _______________

  4. 6x4x96 - x \ge 4x - 9 Solution: _______________

  5. Rewrite 20>5x20 > 5x with the variable first: _______________ Then graph it.

  6. Which of 8-8, 3-3, 00, 2.52.5, 77 solve 2x+511-2x + 5 \ge 11?

    Solved form: ____________ Solutions: _______________

  7. An open circle at 32\tfrac{3}{2} shaded right.

    Inequality: _______________ A multistep inequality with the same solution set: _______________

    Show that it does: _______________________________________________


PAGE 26 — Chapter 3 review, part 3

Chapter 3 Review (continued)

  1. Apply it. A hiker starts at 2{,}400 feet and descends 150 feet per hour, so her elevation after hh hours is 2,400150h2{,}400 - 150h feet.

    Inequality for "below 1{,}500 feet": _______________ Solution: _______________

    Graph it. Which part of the graph describes no real moment? _______________________________________________

  2. Explain. State the complete rule for reversing the symbol.


    An example that reverses: _______________ Solution: ____________

    An example with several minus signs and no reversal: _______________ Solution: ____________


PAGE 27 — Chapter 3 review, part 4

Chapter 3 Review (continued)

Part B · Verifying and interpreting (A.EI.1f)

  1. 94x259 - 4x \le 25 Solution: _______________

    Inside: ______ Boundary: ______ Outside: ______

  2. Verify graphically that 3x2<x+43x - 2 < x + 4 solves to x<3x < 3.

    The two lines: ____________ and ____________ They cross at ( ______ , ______ )

    Which line is lower to the left of the crossing? ____________

  3. Use the table to estimate where 2x+18x2x + 1 \ge 8 - x.

xx 0 1 2 3 4 5
Y1=2x+1Y_1 = 2x + 1 1 3 5 7 9 11
Y2=8xY_2 = 8 - x 8 7 6 5 4 3
From the table, the boundary is between ______ and ______ .   Solved algebraically: _______________

Why can the table not give the exact boundary? _______________________________________________
  1. How would you verify a solution set with a graphing calculator, and what would you do if the calculator and your algebra disagreed?



PAGE 28 — Chapter 3 review, part 5

Chapter 3 Review (continued)

  1. Apply it. Gym A: $40\$40 per month plus $6\$6 per class. Gym B: $70\$70 per month plus $2\$2 per class.

    Inequality for "A costs no more than B": _______________ Solution: _______________

    Whole classes: ______

  2. Apply it. A rain barrel holds 90 gallons and loses 6 gallons per day, so it holds 906d90 - 6d gallons after dd days.

    Inequality for "more than 30 gallons": _______________ Solution: _______________

    Which part of the graph describes no real day? _______________________________________________

  3. Apply it. A delivery service charges a $12.00\$12.00 handling fee plus $7.50\$7.50 per box. A shop will spend at most $60.00\$60.00.

    Inequality: _______________ Solution: _______________ Whole boxes: ______


PAGE 29 — Chapter 3 review, part 6

Chapter 3 Review (continued)

  1. Interpretation. Item 57 gives c28c \le 28 crates; item 83 gives b6.4b \le 6.4 boxes.

    Why is the endpoint part of the answer in one and not the other? _______________________________________________

    The test that settles each: _______________________________________________

  2. Interpretation. A descent gives h>6h > 6 hours, with elevation 2,400150h2{,}400 - 150h feet.

    In a sentence: _______________________________________________

    Elevation at exactly h=6h = 6: ______ Why is h=6h = 6 excluded? ____________________

  3. Explain. A classmate verifies x>5x > 5 by testing only x=10x = 10.

    Why is that incomplete? _______________________________________________

    Tests he is missing: ____________________

    A wrong answer his test would not catch: _______________


PAGE 30 — Chapter 3 review, part 7

Chapter 3 Review (continued)

  1. Find the error. Marcus solves 54x>215 - 4x > 21, reaches 4x>16-4x > 16, and writes x>4x > -4.

    Test x=0x = 0 in the original: ______ True or false? ______

    Correct solution: _______________ Correct graph: _______________________________________________

  2. Write a situation in context for 25+4x8125 + 4x \le 81.

    Situation: _______________________________________________


    Solution: _______________ Boundary test: ______ Outside test: ______

    What it means: _______________________________________________


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