Intermediate Algebra for College Students (7th Edition)

Published by Pearson
ISBN 10: 0-13417-894-7
ISBN 13: 978-0-13417-894-3

Chapter 6 - Test - Page 499: 8

Answer

$ \frac{3x-4}{(x-3)(x+2)}$.

Work Step by Step

In order to add the two rational expressions we must determine the Least Common Denominator (LCD). Therefore we need to factor the denominators. Factor $x^2-4x+3$. Rewrite the middle term $-4x$ as $-3x-1x$. $\Rightarrow x^2-3x-1x+3$ Group the terms. $\Rightarrow (x^2-3x)+(-1x+3)$ Factor each group. $\Rightarrow x(x-3)-1(x-3)$ Factor out $(x-3)$. $\Rightarrow (x-3)(x-1)$ Factor $x^2+x-2$. Rewrite the middle term $x$ as $2x-1x$. $\Rightarrow x^2+2x-1x-2$ Group the terms. $\Rightarrow (x^2+2x)+(-1x-2)$ Factor each group. $\Rightarrow x(x+2)-1(x+2)$ Factor out $(x+2)$. $\Rightarrow (x+2)(x-1)$ Back substitute into the given expression. $\Rightarrow \frac{2}{x^2-4x+3}+ \frac{3x}{x^2+x-2}=\frac{2}{(x-3)(x-1)}+ \frac{3x}{(x+2)(x-1)}$ The LCD is $(x-3)(x-1)(x+2)$. Multiply the numerator and the denominator to form LCD at the denominators. $\Rightarrow \frac{2(x+2)}{(x-3)(x-1)(x+2)}+ \frac{3x(x-3)}{(x-3)(x-1)(x+2)}$ Use the distributive property. $\Rightarrow \frac{2x+4}{(x-3)(x-1)(x+2)}+ \frac{3x^2-9x}{(x-3)(x-1)(x+2)}$ Add the numerators because denominators are same. $\Rightarrow \frac{2x+4+3x^2-9x}{(x-3)(x-1)(x+2)}$ Add like terms. $\Rightarrow \frac{3x^2-7x+4}{(x-3)(x-1)(x+2)}$ Factor $3x^2-7x+4$. Rewrite the middle term $-7x$ as $-4x-3x$. $\Rightarrow 3x^2-4x-3x+4$ Group the terms. $\Rightarrow (3x^2-4x)+(-3x+4)$ Factor each group. $\Rightarrow x(3x-4)-1(3x-4)$ Factor out $(3x-4)$. $\Rightarrow (3x-4)(x-1)$ Back substitute into the fraction. $\Rightarrow \frac{(3x-4)(x-1)}{(x-3)(x-1)(x+2)}$ Cancel common factors. $\Rightarrow \frac{3x-4}{(x-3)(x+2)}$.
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.