Basic College Mathematics (9th Edition)

Published by Pearson
ISBN 10: 0321825535
ISBN 13: 978-0-32182-553-7

Chapter 3 - Adding and Subtracting Fractions - 3.4 Adding and Subtracting Mixed Numbers - 3.4 Exercises - Page 228: 23

Answer

Exact answer = $2\frac{5}{8}$

Work Step by Step

$14\frac{7}{8}$ - $12\frac{1}{4}$ Estimation: $14\frac{7}{8} \approx 15$ $12\frac{1}{4} \approx 12$ Therefore $14\frac{7}{8}$ - $12\frac{1}{4}$ $\approx$ 15 - 12 = 3 Exact Calculation: $14\frac{7}{8}$ - $12\frac{1}{4}$ = $14\frac{7}{8}$ - $12\frac{1\times2}{4\times2}$ (8 is the least common denominator) = $14\frac{7}{8}$ - $12\frac{2}{8}$ = $14$ + $\frac{7}{8}$ - ($12$ + $\frac{2}{8})$ = $14$ + $\frac{7}{8}$ - $12$ - $\frac{2}{8}$ = ($14$ - $12$) + ($\frac{7}{8}$ - $\frac{2}{8}$) (Solving whole parts separately and fractional parts separately) = $2$ + $\frac{7 - 2}{8}$ = $2$ + $\frac{5}{8}$ = $2\frac{5}{8}$ The estimate was 3, so the exact answer of $2\frac{5}{8}$ is reasonable.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.