College Algebra 7th Edition

Published by Brooks Cole
ISBN 10: 1305115546
ISBN 13: 978-1-30511-554-5

Chapter 5, Systems of Equations and Inequalities - Chapter 5 Test - Page 481: 15

Answer

$\frac{4x-1}{(x-1)^2(x+2)}=\frac{-1}{x+2}+\frac{1}{x-1}+\frac{1}{(x-1)^2}$

Work Step by Step

$\frac{4x-1}{(x-1)^2(x+2)}=\frac{A}{x+2}+\frac{B}{x-1}+\frac{C}{(x-1)^2}$, $A(x-1)^2+B(x-1)(x+2)+C(x+2)$, $A(x^2-2x+1)+B(x^2+x-2)+C(x+2)$, $(A+B)x^2+(-2A+B+C)x+(A-2B+2C)=4x-1$, $\begin{cases} A+B=0\\ -2A+B+C=4\\ A-2B+2C=-1 \end{cases}$, Multiplying Equation 3 by 2 and adding it to Equation 2. $\begin{cases} -2A+B+C=4\\ 2A-4B+4C=-2\\ -- -- -- --\\ -3B+5C=2 \end{cases}$ Multiplying Equation 1 by -1 and adding it to Equation 3. $\begin{cases} -A-B=0\\ A-2B+2C=-1\\ -- -- -- --\\ -3B+2C=-1 \end{cases}$ Multiplying one of the addition results by -1 and adding it to another. $\begin{cases} -3B+5C=2\\ 3B-2C=1\\ -- -- -- --\\ 3C=3 \end{cases}$, thus, $C=1$, substituting back into the Equation, $-3B+5=2, B=1$, substituting back into the Equation, $A+1=0, A=-1$. Therefore, $\frac{4x-1}{(x-1)^2(x+2)}=\frac{-1}{x+2}+\frac{1}{x-1}+\frac{1}{(x-1)^2}$
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.