Precalculus (6th Edition)

Published by Pearson
ISBN 10: 013421742X
ISBN 13: 978-0-13421-742-0

Chapter 9 - Systems and Matrices - Chapter 9 Test Prep - 955 - Page 955: 51

Answer

$\dfrac{5-2x}{(x-1)(x^2+2)}=\dfrac{1}{x-1}-\dfrac{x+3}{x^2+2} $

Work Step by Step

We will write the partial decomposition as: $\dfrac{5-2x}{(x-1)(x^2+2)}=\dfrac{A}{x-1}+\dfrac{Bx+C}{x^2+2} ~~~~(a)$ This implies that $5-2x=A(x^2+2)+(Bx+c)(x-1) ~~~(b)$ Plug $x=1$ to obtain: $A=1$ Now, plug $A=1$ in equation (b) to obtain: $C=-3$ Back substitution $A=1; C=-3$ and $x=-1$ in equation (b). So, the equation (a) becomes: $\dfrac{5-2x}{(x-1)(x^2+2)}=\dfrac{1}{x-1}+\dfrac{-x-3}{x^2+2} \\ \dfrac{5-2x}{(x-1)(x^2+2)}=\dfrac{1}{x-1}-\dfrac{x+3}{x^2+2} $
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.