Page 613 - Basic College Mathematics with Early Integers

590 C HAPTE R 8 I INTRODUCTION TO ALGEBRA

PRACTICE 8 Example 8 Translate each sentence into an equation.

Translate each sentence into an
a. The product of 7 and 6 is 42.
equation.
b. Twice the sum of 3 and 5 is equal to 16.
a. The difference of 110 and 80
is 30. c. The quotient of -45 and 5 yields -9.
b. The product of 3 and the
sum of -9 and 11 amounts Solution:
to 6. the product
a. In words: is 42
c. The quotient of 24 and -6 of 7 and 6
yields -4.
T T T
#
Translate: 7 6 = 42
the sum of
b. In words: twice is equal to 16
3 and 5
T T T T
Translate: 2 13 + 52 = 16

the quotient
c. In words: yields 9
of 45 and 5
T T T
-45
Translate: = -9
5
Work Practice 8

Calculator Explorations Checking Possible Solutions

A calculator can be used to check possible solutions of Since the left side equals the right side, 7 is a solution of
equations. To do this, replace the variable by the possible the equation 52x = 15x + 259.
solution and evaluate each side of the equation sepa-
rately. For example, to see whether 7 is a solution of the Use a calculator to determine whether the numbers given
equation 52x = 15x + 259, replace x with 7 and use your are solutions of each equation.
calculator to evaluate each side separately.
1. 761x - 252 =-988; 12
Equation: 52x = 15x + 259 2. -47x + 862 =-783; 35
#
#
52 7 15 7 + 259 Replace x with 7. 3. x + 562 = 3x + 900; -170
Evaluate left side: 52 7 = or ENTER . 4. 551x + 102 = 75x + 910; -18
Display: 364 5. 29x - 1034 = 61x - 362; -21
Evaluate right side: 15 7 + 259 = 6. -38x + 205 = 25x + 120; 25
or ENTER . Display: 364 .

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Answers
8. a. 110 - 80 = 30
24
b. 31-9 + 112 = 6 c. =-4
-6