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7.2 Commutative and Associative Properties

Reordering and regrouping addends or factors, and using that freedom to pair convenient numbers when evaluating or simplifying a long expression.

Prealgebra 2e, 7.2 Commutative and Associative Properties

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72 exercises

7.2 Exercise 1

Before you get started, take this readiness quiz.

Simplify: 7y+2+y+13.7 y + 2 + y + 13 .
If you missed this problem, review the reference.

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7.2 Exercise 2

Multiply: 23·18.\frac{2}{3} \cdot 18 .
If you missed this problem, review the reference.

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7.2 Exercise 3

Find the opposite of 15.15 .
If you missed this problem, review the reference.

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7.2 Exercise 4

Use the commutative properties to rewrite the following expressions:

  1. ⓐ −1+3=_____−1 + 3 = _____

  2. ⓑ 4·9=_____4 \cdot 9 = _____

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7.2 Exercise 5

Use the commutative properties to rewrite the following:

  1. ⓐ −4+7=_____−4 + 7 = _____
  2. ⓑ 6·12=_____6 \cdot 12 = _____

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7.2 Exercise 6

Use the commutative properties to rewrite the following:

  1. ⓐ 14+(−2)=_____14 + \left(−2\right) = _____
  2. ⓑ 3(−5)=_____3 \left(−5\right) = _____

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7.2 Exercise 7

Use the associative properties to rewrite the following:

  1. ⓐ (3+0.6)+0.4=__________\left(3 + 0.6\right) + 0.4 = __________

  2. ⓑ (−4·25)·15=__________\left(−4 \cdot \frac{2}{5}\right) \cdot 15 = __________

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7.2 Exercise 8

Use the associative properties to rewrite the following:
ⓐ (1+0.7)+0.3=__________\left(1 + 0.7\right) + 0.3 = __________ ⓑ (−9·8)·34=__________\left(−9 \cdot 8\right) \cdot \frac{3}{4} = __________

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7.2 Exercise 9

Use the associative properties to rewrite the following:
ⓐ (4+0.6)+0.4=__________\left(4 + 0.6\right) + 0.4 = __________ ⓑ (−2·12)·56=__________\left(−2 \cdot 12\right) \cdot \frac{5}{6} = __________

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7.2 Exercise 10

Use the Associative Property of Multiplication to simplify: 6(3x).6 \left(3 x\right) .

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7.2 Exercise 11

Use the Associative Property of Multiplication to simplify the given expression: 8(4x).8 \left(4 x\right) .

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7.2 Exercise 12

Use the Associative Property of Multiplication to simplify the given expression: −9(7y).−9 \left(7 y\right) .

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7.2 Exercise 14

Evaluate each expression when y=38:y = \frac{3}{8} :ⓐ y+0.84+(−y)y + 0.84 + \left(- y\right) ⓑ y+(−y)+0.84.y + \left(- y\right) + 0.84 .

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7.2 Exercise 15

Evaluate each expression when f=1720:f = \frac{17}{20} :ⓐ f+0.975+(−f)f + 0.975 + \left(- f\right) ⓑ f+(−f)+0.975.f + \left(- f\right) + 0.975 .

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7.2 Exercise 17

Evaluate each expression when p=24:p = 24 :ⓐ 59(95p)\frac{5}{9} \left(\frac{9}{5} p\right) ⓑ (59·95)p.\left(\frac{5}{9} \cdot \frac{9}{5}\right) p .

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7.2 Exercise 18

Evaluate each expression when q=15:q = 15 :ⓐ 711(117q)\frac{7}{11} \left(\frac{11}{7} q\right) ⓑ (711·117)q\left(\frac{7}{11} \cdot \frac{11}{7}\right) q

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7.2 Exercise 19

Simplify: −84n+(−73n)+84n.−84 n + \left(−73 n\right) + 84 n .

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7.2 Exercise 20

Simplify: −27a+(−48a)+27a.−27 a + \left(−48 a\right) + 27 a .

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7.2 Exercise 21

Simplify: 39x+(−92x)+(−39x).39 x + \left(−92 x\right) + \left(−39 x\right) .

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7.2 Exercise 22

Simplify: 715·823·157.\frac{7}{15} \cdot \frac{8}{23} \cdot \frac{15}{7} .

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7.2 Exercise 23

Simplify: 916·549·169.\frac{9}{16} \cdot \frac{5}{49} \cdot \frac{16}{9} .

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7.2 Exercise 24

Simplify: 617·1125·176.\frac{6}{17} \cdot \frac{11}{25} \cdot \frac{17}{6} .

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7.2 Exercise 25

Simplify: (513+34)+14.\left(\frac{5}{13} + \frac{3}{4}\right) + \frac{1}{4} .

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7.2 Exercise 26

Simplify: (715+58)+38.\left(\frac{7}{15} + \frac{5}{8}\right) + \frac{3}{8} .

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7.2 Exercise 27

Simplify: (29+712)+512.\left(\frac{2}{9} + \frac{7}{12}\right) + \frac{5}{12} .

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7.2 Exercise 28

Simplify: (6.47q+9.99q)+1.01q.\left(6.47 q + 9.99 q\right) + 1.01 q .

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7.2 Exercise 29

Simplify: (5.58c+8.75c)+1.25c.\left(5.58 c + 8.75 c\right) + 1.25 c .

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7.2 Exercise 30

Simplify: (8.79d+3.55d)+5.45d.\left(8.79 d + 3.55 d\right) + 5.45 d .

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7.2 Exercise 31

Simplify the expression: [ 1.67(8) ] (0.25).\left[1.67 \left(8\right)\right] \left(0.25\right) .

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7.2 Exercise 32

Simplify: [1.17(4)](2.25).\left[1.17 \left(4\right)\right] \left(2.25\right) .

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7.2 Exercise 33

Simplify: [3.52(8)](2.5).\left[3.52 \left(8\right)\right] \left(2.5\right) .

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7.2 Exercise 34

Simplify: 6(9x).6 \left(9 x\right) .

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7.2 Exercise 35

Simplify: 8(3y).8 \left(3 y\right) .

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7.2 Exercise 36

Simplify: 12(5z).12 \left(5 z\right) .

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7.2 Exercise 37

Simplify: 18p+6q+(−15p)+5q.18 p + 6 q + \left(−15 p\right) + 5 q .

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7.2 Exercise 38

Simplify: 23r+14s+9r+(−15s).23 r + 14 s + 9 r + \left(−15 s\right) .

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7.2 Exercise 39

Simplify: 37m+21n+4m+(−15n).37 m + 21 n + 4 m + \left(−15 n\right) .

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7.2 Exercise 41

Use the commutative properties to rewrite the given expression.

7+6=___7 + 6 = ___

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7.2 Exercise 43

Use the commutative properties to rewrite the given expression.

7(−13)=___7 \left(−13\right) = ___

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7.2 Exercise 45

Use the commutative properties to rewrite the given expression.

(−12)(−18)=___\left(−12\right) \left(−18\right) = ___

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7.2 Exercise 47

Use the commutative properties to rewrite the given expression.

−15+7=___−15 + 7 = ___

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7.2 Exercise 49

Use the commutative properties to rewrite the given expression.

y+1=___y + 1 = ___

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7.2 Exercise 51

Use the commutative properties to rewrite the given expression.

−3m=___−3 m = ___

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7.2 Exercise 53

Use the associative properties to rewrite the given expression.

(21+14)+9=___\left(21 + 14\right) + 9 = ___

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7.2 Exercise 55

Use the associative properties to rewrite the given expression.

(14·6)·9=___\left(14 \cdot 6\right) \cdot 9 = ___

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7.2 Exercise 57

Use the associative properties to rewrite the given expression.

(−2+6)+7=___\left(−2 + 6\right) + 7 = ___

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7.2 Exercise 59

Use the associative properties to rewrite the given expression.

(13·23)·18=___\left(13 \cdot \frac{2}{3}\right) \cdot 18 = ___

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7.2 Exercise 61

Use the associative properties to rewrite the given expression.

4(7x)=___4 \left(7 x\right) = ___

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7.2 Exercise 63

Use the associative properties to rewrite the given expression.

(17+y)+33=___\left(17 + y\right) + 33 = ___

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7.2 Exercise 65

Evaluate each expression for the given value.

If z=78,z = \frac{7}{8} , evaluate:

  1. ⓐ z+0.97+(−z)z + 0.97 + \left(- z\right)
  2. ⓑ z+(−z)+0.97z + \left(- z\right) + 0.97

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7.2 Exercise 67

Evaluate each expression for the given value.

If d=−94,d = - \frac{9}{4} , evaluate:

  1. ⓐ d+2.375+(−d)d + 2.375 + \left(- d\right)
  2. ⓑ d+(−d)+2.375d + \left(- d\right) + 2.375

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7.2 Exercise 69

Evaluate each expression for the given value.

If k=21,k = 21 , evaluate:

  1. ⓐ 413(134k)\frac{4}{13} \left(\frac{13}{4} k\right)
  2. ⓑ (413·134)k\left(\frac{4}{13} \cdot \frac{13}{4}\right) k

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7.2 Exercise 71

Evaluate each expression for the given value.

If n=−8,n = −8 , evaluate:

  1. ⓐ −521(215n)- \frac{5}{21} \left(\frac{21}{5} n\right)
  2. ⓑ (−521·215)n\left(- \frac{5}{21} \cdot \frac{21}{5}\right) n

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7.2 Exercise 73

Simplify.

9y+23+(−9y)9 y + 23 + \left(−9 y\right)

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7.2 Exercise 75

Simplify.

25+512+(−25)\frac{2}{5} + \frac{5}{12} + \left(- \frac{2}{5}\right)

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7.2 Exercise 77

Simplify.

1318·257·1813\frac{13}{18} \cdot \frac{25}{7} \cdot \frac{18}{13}


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7.2 Exercise 79

Simplify.

310·1323·503\frac{3}{10} \cdot \frac{13}{23} \cdot \frac{50}{3}

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7.2 Exercise 81

Simplify.

−36·11·49−36 \cdot 11 \cdot \frac{4}{9}

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7.2 Exercise 83

Simplify.

(112+49)+59\left(\frac{1}{12} + \frac{4}{9}\right) + \frac{5}{9}

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7.2 Exercise 85

Simplify.

815+57+27\frac{8}{15} + \frac{5}{7} + \frac{2}{7}

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7.2 Exercise 87

Simplify.

(5.89d+2.75d)+1.25d\left(5.89 d + 2.75 d\right) + 1.25 d

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7.2 Exercise 89

Simplify.

36(0.2)(5)36 \left(0.2\right) \left(5\right)

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7.2 Exercise 91

Simplify.

[9.731(4)](0.75)\left[9.731 \left(4\right)\right] \left(0.75\right)

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7.2 Exercise 93

Simplify.

9(8w)9 \left(8 w\right)

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7.2 Exercise 95

Simplify.

−23(2n)−23 \left(2 n\right)

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7.2 Exercise 97

Simplify.

20(35q)20 \left(\frac{3}{5} q\right)

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7.2 Exercise 99

Simplify.

15u+11v+27u+19v15 u + 11 v + 27 u + 19 v

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7.2 Exercise 101

Simplify.

−22p+17q+(−35p)+(−27q)−22 p + 17 q + \left(−35 p\right) + \left(−27 q\right)

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7.2 Exercise 103

Simplify.

56a+310b+16a+910b\frac{5}{6} a + \frac{3}{10} b + \frac{1}{6} a + \frac{9}{10} b

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7.2 Exercise 105

Simplify.

9.6m+7.22n+(−2.19m)+(−0.65n)9.6 m + 7.22 n + \left(−2.19 m\right) + \left(−0.65 n\right)

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7.2 Exercise 107

Counting Cash Grant is totaling up the cash from a fundraising dinner. In one envelope, he has twenty-three $5\$\text{5} bills, eighteen $10\$\text{10} bills, and thirty-four $20\$\text{20} bills. In another envelope, he has fourteen $5\$\text{5} bills, nine $10\$\text{10} bills, and twenty-seven $20\$\text{20} bills.

  1. ⓐ How much money is in the first envelope?

  2. ⓑ How much money is in the second envelope?

  3. ⓒ What is the total value of all the cash?

  4. ⓓ What is the va…

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7.2 Exercise 109

In your own words, state the Associative Property of Multiplication and explain why it is useful.

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Adapted from Prealgebra 2e © 2020 Rice University. Licensed under CC BY 4.0. Source: Prealgebra 2e. Imported at revision 77a933c.