Page 349 - Basic College Mathematics with Early Integers

326 C HAPTE R 4 I DECIMALS

PRACTICE 11 Example 11 Simplify: 723.6 , 1000 * 10
Simplify: 897.8 , 100 * 10
Solution: Multiply or divide in order from left to right.
723.6 , 1000 * 10 = 0.7236 * 10 Divide.
= 7.236 Multiply.
Work Practice 11

PRACTICE 12 Example 12 Simplify: -0.5(8.6 - 1.2)
Simplify: -8.69(3.2 - 1.8)
Solution: According to the order of operations, we simplify inside the parentheses
first.
-0.5(8.6 - 1.2) =-0.5(7.4) Subtract.
=-3.7 Multiply.
Work Practice 12

13 2
PRACTICE 13 Example 13 Simplify: a- b + 2.4
10
2
7
Simplify: a - b + 2.1
10 Solution: Recall the meaning of an exponent.
13 2 13 13
a - b + 2.4 = a - b a - b + 2.4 Use the definition of an exponent.
10 10 10
169 Multiply.The product of two negative num-
= + 2.4
100 bers is a positive number.
169
= 1.69 + 2.4 Write as a decimal.
100
= 4.09 Add.
Work Practice 13

2
5.68 + (0.9) , 100
PRACTICE 14 Example 14 Simplify:
0.2
2
20.06 - (1.2) , 10
Simplify:
0.02 Solution: First we simplify the numerator of the fraction.Then we divide.
2
5.68 + (0.9) , 100 5.68 + 0.81 , 100
= Simplify (0.9) .
2
0.2 0.2
5.68 + 0.0081
= Divide.
0.2
5.6881
= Add.
0.2
= 28.4405 Divide.
Work Practice 14

Objective Solving Area Problems Containing Fractions
and Decimals Copyright 2012 Pearson Education, Inc.
Sometimes real-life problems contain both fractions and decimals. In the next
Answers
example, we review the area of a triangle, and when values are substituted, the
11. 89.78 12. -12.166 13. 2.59
result may be an expression containing both fractions and decimals.
14. 995.8