1.3E: Exercises
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Practice Makes Perfect
Use Variables and Algebraic Symbols
In the following exercises, translate from algebra to English.
16−9
- Answer
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16 minus 9, the difference of sixteen and nine
3⋅9
28÷4
- Answer
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28 divided by 4, the quotient of twenty-eight and four
x+11
(2)(7)
- Answer
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2 times 7, the product of two and seven
(4)(8)
14<21
- Answer
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fourteen is less than twenty-one
17<35
36≥19
- Answer
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thirty-six is greater than or equal to nineteen
6n=36
y−1>6
- Answer
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y minus 1 is greater than 6, the difference of y and one is greater than six
y−4>8
2≤18÷6
- Answer
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2 is less than or equal to 18 divided by 6; 2 is less than or equal to the quotient of eighteen and six
a≠1⋅12
In the following exercises, determine if each is an expression or an equation.
9⋅6=54
- Answer
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equation
7⋅9=63
5⋅4+3
- Answer
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expression
x+7
x+9
- Answer
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expression
y−5=25
Simplify Expressions Using the Order of Operations
In the following exercises, simplify each expression.
53
- Answer
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125
83
28
- Answer
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256
105
In the following exercises, simplify using the order of operations.
- 3+8⋅5
- (3+8)⋅5
- Answer
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- 43
- 55
- 2+6⋅3
- (2+6)⋅3
23−12÷(9−5)
- Answer
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5
32−18÷(11−5)
3⋅8+5⋅2
- Answer
-
34
4⋅7+3⋅5
2+8(6+1)
- Answer
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58
4+6(3+6)
4⋅12/8
- Answer
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6
2⋅36/6
(6+10)÷(2+2)
- Answer
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4
(9+12)÷(3+4)
20÷4+6⋅5
- Answer
-
35
33÷3+8⋅2
32+72
- Answer
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58
(3+7)2
3(1+9⋅6)−42
- Answer
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149
5(2+8⋅4)−72
2[1+3(10−2)]
- Answer
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50
5[2+4(3−2)]
Evaluate an Expression
In the following exercises, evaluate the following expressions.
7x+8 when x=2
- Answer
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22
8x−6 when x=7
x2 when x=12
- Answer
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144
x3 when x=5
x5 when x=2
- Answer
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32
4x when x=2
x2+3x−7 when x=4
- Answer
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21
6x+3y−9 when x=10,y=7
- Answer
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9
(x+y)2 when x=6,y=9
a2+b2 when a=3,b=8
- Answer
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73
r2−s2 when r=12,s=5
2l+2w when l=15,w=12
- Answer
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54
2l+2w when l=18,w=14
Simplify Expressions by Combining Like Terms
In the following exercises, identify the coefficient of each term.
8a
- Answer
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8
13m
5r2
- Answer
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5
6x3
In the following exercises, identify the like terms.
x3,8x,14,8y,5,8x3
- Answer
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x3 and 8x3, 14 and 5
6z,3w2,1,6z2,4z,w2
9a,a2,16,16b2,4,9b2
- Answer
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16 and 4, 16b2 and 9b2
3,25r2,10s,10r,4r2,3s
In the following exercises, identify the terms in each expression.
15x2+6x+2
- Answer
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15x2,6x,2
11x2+8x+5
10y3+y+2
- Answer
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10y3,y,2
9y3+y+5
In the following exercises, simplify the following expressions by combining like terms.
10x+3x
- Answer
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13x
15x+4x
4c+2c+c
- Answer
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7c
6y+4y+y
7u+2+3u+1
- Answer
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10u+3
8d+6+2d+5
10a+7+5a−2+7a−4
- Answer
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22a+1
7c+4+6c−3+9c−1
3x2+12x+11+14x2+8x+5
- Answer
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17x2+20x+16
5b2+9b+10+2b2+3b−4
Translate an English Phrase to an Algebraic Expression
In the following exercises, translate the phrases into algebraic expressions.
the difference of 14 and 9
- Answer
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14−9
the difference of 19 and 8
the product of 9 and 7
- Answer
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9⋅7
the product of 8 and 7
the quotient of 36 and 9
- Answer
-
36÷9
the quotient of 42 and 7
the sum of 8x and 3x
- Answer
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8x+3x
the sum of 13x and 3x
the quotient of y and 3
- Answer
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y3
the quotient of y and 8
eight times the difference of y and nine
- Answer
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8(y−9)
seven times the difference of y and one
Eric has rock and classical CDs in his car. The number of rock CDs is 3 more than the number of classical CDs. Let c represent the number of classical CDs. Write an expression for the number of rock CDs.
- Answer
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c+3
The number of girls in a second-grade class is 4 less than the number of boys. Let b represent the number of boys. Write an expression for the number of girls.
Greg has nickels and pennies in his pocket. The number of pennies is seven less than twice the number of nickels. Let n represent the number of nickels. Write an expression for the number of pennies.
- Answer
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2n−7
Jeannette has $5 and $10 bills in her wallet. The number of fives is three more than six times the number of tens. Let t represent the number of tens. Write an expression for the number of fives.
Everyday Math
Car insurance Justin’s car insurance has a $750 deductible per incident. This means that he pays $750 and his insurance company will pay all costs beyond $750. If Justin files a claim for $2,100.
- how much will he pay?
- how much will his insurance company pay?
- Answer
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- $750
- $1,350
Home insurance Armando’s home insurance has a $2,500 deductible per incident. This means that he pays $2,500 and the insurance company will pay all costs beyond $2,500. If Armando files a claim for $19,400.
- how much will he pay?
- how much will the insurance company pay?
Writing Exercises
Explain the difference between an expression and an equation.
- Answer
-
Answers may vary
Why is it important to use the order of operations to simplify an expression?
Explain how you identify the like terms in the expression 8a2+4a+9−a2−1
- Answer
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Answers may vary
Explain the difference between the phrases “4 times the sum of x and y” and “the sum of 4 times x and y.”
Self Check
ⓐ Use this checklist to evaluate your mastery of the objectives of this section.
ⓑ After reviewing this checklist, what will you do to become confident for all objectives?