Page 237 - Basic College Mathematics with Early Integers

214 C HAPTE R 3 I FRACTIONS

3
PRACTICE 16 Example 16 Write as an equivalent fraction with a denominator of 20.
4
7
Write as an equivalent fraction 3
8 =
with a denominator of 56. 4 20
#
Solution: In the denominators, since 4 5 = 20, we will multiply by 1 in the form
7
= 5
8 56 of .
5
#
#
3 = 3 5 = 3 5 = 15
#
4 4 5 4 5 20
3 15
Thus, = .
4 20
Work Practice 16

15
To check Example 16, write in simplest form.
20
1
15 3 # 5 3
= = , the original fraction.
20 4 # 5 4
1
If the original fraction is in lowest terms, we can check our work by writing the
new, equivalent fraction in simplest form.This form should be the original fraction.

2
Concept Check True or false? When the fraction is rewritten as an
9
2
equivalent fraction with 27 as the denominator, the result is .
27
PRACTICE 17 Example 17 Write an equivalent fraction with the given denominator.
Write an equivalent fraction
with the given denominator. 2 =
1 5 15
= 3
#
4 44 Solution: Since 5 3 = 15 , we multiply by 1 in the form of .
3
#
2 = 2 # 3 = 2 3 = 6
#
5 5 3 5 3 15
2 6
Then is equivalent to .They both represent the same part of a whole.
5 15
Work Practice 17

PRACTICE 18 Example 18 Write an equivalent fraction with the given denominator.
Write an equivalent fraction
with the given denominator. 3 =
7
4 = 3 7
#
6 Solution: Recall that 3 = . Since 1 7 = 7, multiply by 1 in the form .
1 7
#
Answers 3 3 # 7 3 7 21
49 11 24 = = # =
16. 17. 18. 1 1 7 1 7 7
56 44 6 Copyright 2012 Pearson Education, Inc.
Work Practice 18
Concept Check Answers 3
6 Concept Check What is the first step in writing as an equivalent frac-
false; the correct result would be
27 tion whose denominator is 100? 10
answers may vary