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Virginia SOL Mathematics Textbook

Grade 7 Workbook — Chapter 9: Equivalent Algebraic Expressions

SOL 7.PFA.2 (b–d) · Companion to Textbook Chapter 9

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 120.


PAGE 1 — Chapter opener

Chapter 9 · Equivalent Algebraic Expressions

Standard 7.PFA.2 (b–d)

In this chapter you will:

Words to know: algebraic expression · variable · equivalent · algebra tile · xx-tile · unit tile · colored chip · zero pair · term · coefficient · constant · like terms · distributive property · evaluate · replacement value

Calculator note: simplifying algebraic expressions is tested without a calculator. Every number on pages 2 through 17 is mental-math sized.


PAGE 2 — The pieces and what they are worth

9.1 Modeling with Tiles and Chips

FIGURE: fig1-tile-and-chip-key.png (full width)

Fill in the blanks.

A long rectangle is an ________-tile. It is worth ________.

A small square is a ________ tile. It is worth ________.

Blue pieces are ____________ and red pieces are ____________.

We never say how many unit tiles fit inside an xx-tile, because xx is ____________.

FIGURE: fig2-model-3x-plus-2.png (full width)

  1. A model shows three xx-tiles and two positive unit tiles. Write the expression.

    Expression: _______________

Draw the tiles. Use a long rectangle for an xx-tile and a small square for a unit tile. Shade negative pieces.

  1. 2x+52x + 5

    TILE DRAWING SPACE: 1.5 in tall, full width

  2. x+4-x + 4

    TILE DRAWING SPACE: 1.5 in tall, full width


PAGE 3 — Reading and writing models

From Tiles to Symbols and Back

  1. A model shows four xx-tiles and three negative unit tiles.

    Expression: _______________

  2. What is the value of one zero pair? ______

    Why does removing one leave the total unchanged?


  3. A model shows three xx-tiles and two negative xx-tiles. Cross out the zero pairs above, then write what remains.

    TILE DRAWING SPACE: 1.2 in tall, full width — pre-drawn 3 positive x-tiles and 2 negative x-tiles

    What remains: _______________

  4. Write the expression modeled by each set of tiles.

Model Expression
a) two xx-tiles and six negative unit tiles
b) three negative xx-tiles and one positive unit tile
c) one xx-tile and five positive unit tiles
  1. Describe a tile model for 2x3-2x - 3.



PAGE 4 — Chips and zero pairs

Chips, Zero Pairs, and Equivalence

FIGURE: fig3-zero-pairs.png (full width)

FIGURE: fig4-chip-value.png (full width)

  1. Seven positive chips and four negative chips. Value: ______

  2. Five negative chips and two positive chips. Value: ______

  3. Model 4x+(4x)4x + (-4x) with tiles. What is left?

    TILE DRAWING SPACE: 1.2 in tall, full width

    Explain why the expression is equivalent to 00.


  4. Model A: three xx-tiles and two negative unit tiles. Model B: one xx-tile, five negative unit tiles, two xx-tiles, and three positive unit tiles.

    Model A simplifies to: _______________

    Model B simplifies to: _______________

    Equivalent? ______ How do you know?


  5. Apply it. A concert ticket costs xx dollars and the site adds a flat $2 fee to the order. Write an expression for three tickets plus the fee, then describe the model.

    Expression: _______________ Model: _______________________________________________

  6. Find the error. To model 52x5 - 2x, a student lays out five negative unit tiles and two positive xx-tiles.

    What went wrong? _______________________________________________

    Correct model: _______________________________________________


PAGE 5 — Exit ticket 9.1

Exit Ticket · Lesson 9.1

Name: ________________________ Date: ____________

  1. Write the expression modeled by two xx-tiles and four negative unit tiles. _______________

  2. Describe a tile model for 3x+1-3x + 1.


  3. A model shows five xx-tiles and three negative xx-tiles. What remains after all zero pairs are removed? ______

  4. Why is one positive chip together with one negative chip worth zero?



PAGE 6 — Terms, coefficients, constants

9.2 Like Terms

Rewrite every subtraction as adding the opposite first. The sign in front of a term BELONGS to that term.

Complete the table.

Expression Terms Coefficient of xx Constant
7x47x - 4
x+9-x + 9
83x8 - 3x
23x\tfrac{2}{3}x none
  1. In 7x47x - 4: coefficient ______ constant ______

  2. How many terms are in 3x+52x3x + 5 - 2x? ______

  3. In x+9-x + 9, the coefficient of xx is ______

  4. Are 4x4x and 44 like terms? ______ Why?


  5. Like terms in 6x3+2x+86x - 3 + 2x + 8: ______ and ______ ; ______ and ______

  6. Are 0.5x0.5x and 34x-\tfrac{3}{4}x like terms? ______


PAGE 7 — Sorting practice

Sorting Terms

  1. List the terms of 5x7+x5x - 7 + x: ______ , ______ , ______

  2. Name the coefficient.

a) 9x9x b) x-x c) 23x\tfrac{2}{3}x d) 2.5x-2.5x
  1. Circle YES or NO for each pair of like terms.
a) 3x3x and 8x-8x YES / NO
b) 55 and 2-2 YES / NO
c) 7x7x and 77 YES / NO
d) 12x-\tfrac{1}{2}x and 4x4x YES / NO
  1. Sort the terms of 2x+6+5x11-2x + 6 + 5x - 11.

    xx-terms: _______________ constants: _______________

  2. Explain. Using algebra tiles, why are 3x3x and 33 not like terms?



PAGE 8 — Testing and correcting

Test It, Then Fix It

  1. Are x+x+xx + x + x and 3x3x equivalent?
xx x+x+xx + x + x 3x3x
44
2-2
What do the models look like? _______________________________________________
  1. Apply it. A rectangle has length xx cm and width 33 cm. Its perimeter is x+3+x+3x + 3 + x + 3.

    Like terms: ______ and ______ ; ______ and ______

  2. Find the error. A student says the coefficient of xx in 83x8 - 3x is 33.

    What went wrong? _______________________________________________

    Correct coefficient: ______


PAGE 9 — Exit ticket 9.2

Exit Ticket · Lesson 9.2

Name: ________________________ Date: ____________

  1. In 6x+2.5-6x + 2.5: coefficient ______ constant ______

  2. Are 13x-\tfrac{1}{3}x and 7x7x like terms? ______ Why?


  3. How many terms are in 4x9+x4x - 9 + x? ______

  4. What makes two terms like terms?



PAGE 10 — Combining like terms

9.3 Combining Like Terms

FIGURE: fig5-combining-like-terms.png (full width)

Why it works — fill in the frame.

5x+3x=(    +    )x=    x5x + 3x = (\underline{\ \ \ \ } + \underline{\ \ \ \ })x = \underline{\ \ \ \ }x

Pulling the common factor xx out front is the ______________ property read backwards.

Simplify. Use the step frame for items 41 and 42.

  1. 4x+3x=4x + 3x = ______

  2. 9x2x=9x - 2x = ______

  3. 5x+2+3x=5x + 2 + 3x = ______

  4. 3x+7x=-3x + 7x = ______

  5. 64x96 - 4x - 9

    As a sum: _______________ Combine: _______________

  6. 2x57x+12x - 5 - 7x + 1

    As a sum: _______________ xx-terms: _______________ constants: _______________

    Simplified: _______________

  7. 0.5x+1.5x=0.5x + 1.5x = ______

  8. 14x+12x=\tfrac{1}{4}x + \tfrac{1}{2}x = ______


PAGE 11 — More practice

Practice · Combining Like Terms

  1. Simplify.
a) 8x12x8x - 12x b) x+6x-x + 6x c) 3.2x1.2x3.2x - 1.2x d) 23x13x-\tfrac{2}{3}x - \tfrac{1}{3}x
  1. 7x+42x9=7x + 4 - 2x - 9 = _______________

  2. 5+3x+810x=-5 + 3x + 8 - 10x = _______________

  3. 12x+32x+12=\tfrac{1}{2}x + 3 - 2x + \tfrac{1}{2} = _______________

  4. 2.5x4+2.5x+4=-2.5x - 4 + 2.5x + 4 = _______________

  5. 6xx+33=6x - x + 3 - 3 = _______________


PAGE 12 — Reasoning and application

Why It Works

  1. Explain. Use the distributive property to show why 5x+3x=8x5x + 3x = 8x.


    Why does the same reasoning NOT turn 5x+35x + 3 into 8x8x?


  2. Show 4xx+24x - x + 2 and 3x+23x + 2 are equivalent.

    Simplify 4xx+24x - x + 2: _______________

xx 4xx+24x - x + 2 3x+23x + 2
55
2-2
  1. Apply it. A triangle has sides xx, x+4x + 4, and 2x12x - 1 inches.

    Perimeter expression: _______________ Simplified: _______________

  2. Find the error. A student simplifies 94x9 - 4x to 5x5x.

    What went wrong? _______________________________________________

    Correct answer: _______________


PAGE 13 — Exit ticket 9.3

Exit Ticket · Lesson 9.3

Name: ________________________ Date: ____________

  1. 3x+8x=3x + 8x = ______

  2. 6x+2+x9=-6x + 2 + x - 9 = _______________

  3. 34x14x=\tfrac{3}{4}x - \tfrac{1}{4}x = ______

  4. Why can 7x77x - 7 not be simplified any further?



PAGE 14 — The distributive property

9.4 Distributing with Variables

FIGURE: fig6-area-model-distribution.png (full width)

a(b+c)=ab+aca(b + c) = ab + ac

The outside factor multiplies EVERY term inside.

Watch the signs. 3(x6)=(3)(x)+(3)(6)=3x+    -3(x - 6) = (-3)(x) + (-3)(-6) = -3x + \underline{\ \ \ \ }

Expand. Use the arrows to show both products.

  1. 3(x+4)=3(x + 4) = _______________

  2. 2(x5)=2(x - 5) = _______________

  3. 4(x+2)=-4(x + 2) = _______________

  4. 5(2x3)=5(2x - 3) = _______________

  5. (x7)=-(x - 7) = _______________

  6. 12(6x+8)=\tfrac{1}{2}(6x + 8) = _______________

  7. 3(x+2)+4x3(x + 2) + 4x

    Distribute: _______________ Combine: _______________

  8. 2(x+3)(x+1)2(x + 3) - (x + 1)

    Distribute: _______________ Combine: _______________


PAGE 15 — Expand and simplify

Practice · Distribute, Then Combine

  1. Expand.
a) 6(x+1)6(x + 1) b) 2(3x5)-2(3x - 5)
c) 0.5(4x+2)0.5(4x + 2) d) (2x+9)-(2x + 9)
  1. 4(x2)+3(x+5)=4(x - 2) + 3(x + 5) = _______________

  2. 5(2x+1)3(x4)=5(2x + 1) - 3(x - 4) = _______________

  3. 3(x6)2x=-3(x - 6) - 2x = _______________

  4. 23(3x9)+4=\tfrac{2}{3}(3x - 9) + 4 = _______________


PAGE 16 — Reasoning, application, error hunt

Show What You Know

  1. Explain. Use the area model to explain why 3(x+4)=3x+123(x + 4) = 3x + 12.

    The left region represents _______________

    The right region represents _______________

    Together: _______________________________________________

  2. Apply it. Four identical party bags each hold xx stickers and 33 erasers.

    With parentheses: _______________ Expanded: _______________

  3. Find the error. A student writes 3(x2)=3x6-3(x - 2) = -3x - 6.

    What went wrong? _______________________________________________

    Correct answer: _______________


PAGE 17 — Exit ticket 9.4

Exit Ticket · Lesson 9.4

Name: ________________________ Date: ____________

  1. 7(x3)=7(x - 3) = _______________

  2. 2(x+4)+3x=2(x + 4) + 3x = _______________

  3. (x5)+2x=-(x - 5) + 2x = _______________

  4. Why must the outside factor multiply every term inside?



PAGE 18 — Substituting a value

9.5 Evaluating Expressions

Always substitute inside parentheses. 3x+53x + 5 at x=2x = -2 becomes 3(    )+5=    3(\underline{\ \ \ \ }) + 5 = \underline{\ \ \ \ }

Evaluate. Show the substitution step.

  1. 3x+53x + 5 at x=4x = 4: 3(    )+5=3(\underline{\ \ \ \ }) + 5 = ______

  2. 3x+53x + 5 at x=2x = -2: 3(    )+5=3(\underline{\ \ \ \ }) + 5 = ______

  3. 2x+7-2x + 7 at x=3x = 3: _______________ == ______

  4. 4x94x - 9 at x=12x = -\tfrac{1}{2}: _______________ == ______

  5. x+23x + 2^3 at x=5x = -5: _______________ == ______

  6. 5x365x - \sqrt{36} at x=2x = 2: _______________ == ______

  7. x+4|x| + 4 at x=7x = -7: _______________ == ______

  8. 2[x+3]12[x + 3] - 1 at x=4x = -4: _______________ == ______


PAGE 19 — Evaluation practice

Practice · Evaluating

  1. 6x46x - 4
x=3x = 3 x=3x = -3 x=0.5x = 0.5
  1. x+10-x + 10
x=12x = 12 x=6x = -6 x=13x = \tfrac{1}{3}
  1. 3[2x5]+493[2x - 5] + \sqrt{49} at x=4x = 4: _______________ == ______

  2. 243x2^4 - 3x at x=2x = -2: _______________ == ______

  3. 2x5|2x| - 5 at x=3x = -3: _______________ == ______


PAGE 20 — Equivalence and error hunt

Simplify First, Then Check

FIGURE: fig7-equivalence-substitution.png (full width)

  1. Simplify 4(x1)+2x4(x - 1) + 2x: _______________
xx 4(x1)+2x4(x - 1) + 2x simplified form
33
12-\tfrac{1}{2}
What do the results show? _______________________________________________
  1. Apply it. A kayak rental costs $12 per hour plus a $5 launch fee, so the total is 12h+512h + 5 dollars.

    Cost of a 3-hour rental: $______

  2. Find the error. Asked to evaluate 52x5 - 2x at x=3x = -3, a student writes 523=15 - 2 \cdot 3 = -1.

    What went wrong? _______________________________________________

    Correct value: ______


PAGE 21 — Exit ticket 9.5

Exit Ticket · Lesson 9.5

Name: ________________________ Date: ____________

  1. 7x27x - 2 at x=1x = -1: ______

  2. x+32x + 3^2 at x=4x = -4: ______

  3. x6|x| - 6 at x=10x = -10: ______

  4. Why should you write parentheses around a negative replacement value? Use 52x5 - 2x at x=3x = -3.



PAGE 22 — Chapter 9 review, part 1

Chapter 9 Review

Part A · Modeling with tiles and chips

  1. Three xx-tiles and five negative unit tiles. Expression: _______________

  2. Describe a tile model for 2x+4-2x + 4: _______________________________________________

  3. Six xx-tiles and four negative xx-tiles. After removing zero pairs: _______________

  4. Eight positive chips and eleven negative chips. Value: ______

  5. Explain how zero pairs show 5x+(5x)=05x + (-5x) = 0.



PAGE 23 — Chapter 9 review, part 2

Chapter 9 Review (continued)

Part B · Simplifying and generating equivalent expressions

  1. Simplify.
a) 9x+5x9x + 5x b) 7x+3x-7x + 3x c) 2.5x4.5x2.5x - 4.5x d) 56x13x\tfrac{5}{6}x - \tfrac{1}{3}x
  1. 8x35x+11=8x - 3 - 5x + 11 = _______________

  2. 5(x2)+3x=5(x - 2) + 3x = _______________

  3. 2(4x+1)+6x=-2(4x + 1) + 6x = _______________

  4. 34(8x4)=\tfrac{3}{4}(8x - 4) = _______________

  5. 3(x+5)(2x1)=3(x + 5) - (2x - 1) = _______________

  6. Write two expressions equivalent to 6x+126x + 12. At least one must use parentheses.

    Expression 1: _______________ Expression 2: _______________

    Why is each equivalent? _______________________________________________


PAGE 24 — Chapter 9 review, part 3

Chapter 9 Review (continued)

Part C · Evaluating expressions

  1. 4x74x - 7
x=5x = 5 x=2x = -2 x=14x = \tfrac{1}{4}
  1. 3x+23-3x + 2^3 at x=1x = -1: ______

  2. x+25|x| + \sqrt{25} at x=6x = -6: ______

  3. 2[x4]+92[x - 4] + 9 at x=1.5x = 1.5: ______

  4. 105x10 - 5x at x=0.2x = -0.2: ______


PAGE 25 — Chapter 9 review, part 4

Chapter 9 Review (continued)

Part D · Application and reasoning

  1. Simplify 3(2x1)+43(2x - 1) + 4: _______________
xx 3(2x1)+43(2x - 1) + 4 6x+16x + 1
22
3-3
  1. Apply it. A ride costs $3 plus $2 per mile, so one rider pays 2m+32m + 3 dollars. Two friends each take their own ride of the same length.

    With parentheses: _______________ Simplified: _______________

    Total for a 7-mile trip: $______

  2. Find the error. A student simplifies 42(x+3)4 - 2(x + 3) to 2x+10-2x + 10.

    What went wrong? _______________________________________________

    Correct answer: _______________

  3. Explain. Why is checking one replacement value not enough to prove two expressions are equivalent? Use x+2x + 2 and 3x3x.


  4. Use algebra tiles to justify that 2(x+3)2(x + 3) and 2x+62x + 6 are equivalent.

    TILE DRAWING SPACE: 2 in tall, full width — two groups of (1 x-tile + 3 unit tiles), then one combined row

    Explain: _______________________________________________


Canva production notes