Precalculus (6th Edition)

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

Chapter 9 - Systems and Matrices - 9.4 Partial Fractions - 9.4 Exercises - Page 895: 12

Answer

$$\frac{3}{{x - 3}} + \frac{2}{{x + 1}}$$

Work Step by Step

$$\eqalign{ & \frac{{5x - 3}}{{{x^2} - 2x - 3}} \cr & {\text{Factoring the denominator}} \cr & \frac{{5x - 3}}{{\left( {x - 3} \right)\left( {x + 1} \right)}} \cr & {\text{The partial fraction decomposition is }} \cr & \frac{{5x - 3}}{{\left( {x - 3} \right)\left( {x + 1} \right)}} = \frac{A}{{x - 3}} + \frac{B}{{x + 1}} \cr & {\text{Multiply each side by }}\left( {x - 3} \right)\left( {x + 1} \right) \cr & 5x - 3 = A\left( {x + 1} \right) + B\left( {x - 3} \right)\,\,\,\,\,\,\,\,\,\,\left( 1 \right) \cr & \cr & {\text{Let }}x = 3{\text{ into the equation }}\left( 1 \right) \cr & 5\left( 3 \right) - 3 = A\left( {3 + 1} \right) + B\left( {3 - 3} \right) \cr & 12 = A\left( 4 \right) \cr & A = 3 \cr & {\text{Let }}x = - 1{\text{ into the equation }}\left( 1 \right) \cr & 5\left( { - 1} \right) - 3 = A\left( { - 1 + 1} \right) + B\left( { - 1 - 3} \right) \cr & - 8 = B\left( { - 4} \right) \cr & B = 2 \cr & \cr & {\text{Use }}A{\text{ and }}B{\text{ to find the partial fraction decomposition}} \cr & \frac{{5x - 3}}{{\left( {x - 3} \right)\left( {x + 1} \right)}} = \frac{3}{{x - 3}} + \frac{2}{{x + 1}} \cr} $$
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.