Thinking Mathematically (6th Edition)

Published by Pearson
ISBN 10: 0321867327
ISBN 13: 978-0-32186-732-2

Chapter 5 - Number Theory and the Real Number System - 5.3 The Rational Numbers - Exercise Set 5.3 - Page 285: 82

Answer

\[\left( \frac{193}{432} \right)\].

Work Step by Step

This expression can be reduced by the determination of LCM of denominators of both rational numbers. As,\[108={{2}^{2}}\times {{3}^{3}}\] and\[144={{2}^{4}}\times {{3}^{2}}\]. LCM of \[108\] and 144 is\[{{2}^{4}}\times {{3}^{3}}=432\]. Now, divide\[432\]by\[108\] and \[144\] both. So, \[\begin{align} & \left( \frac{432}{108} \right)=4 \\ & \left( \frac{432}{144} \right)=3 \end{align}\] As, \[\left( \frac{a}{b} \right)=\left( \frac{a.c}{b.c} \right)\] So, \[\begin{align} & \left( \frac{7}{108} \right)=\left( \frac{7\times 4}{108\times 4} \right) \\ & =\left( \frac{28}{432} \right) \end{align}\] And, \[\begin{align} & \left( \frac{55}{144} \right)=\left( \frac{55\times 3}{144\times 3} \right) \\ & =\left( \frac{165}{432} \right) \end{align}\] Now, \[\begin{align} & \left( \frac{7}{108}+\frac{55}{144} \right)=\left( \frac{28}{432}+\frac{165}{432} \right) \\ & =\left( \frac{193}{432} \right) \end{align}\] Therefore, the reduced value of the expression\[\left( \frac{7}{108}+\frac{55}{144} \right)\]is \[\left( \frac{193}{432} \right)\].
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.