College Algebra (6th Edition)

Published by Pearson
ISBN 10: 0-32178-228-3
ISBN 13: 978-0-32178-228-1

Chapter 1 - Equations and Inequalities - Exercise Set 1.6 - Page 179: 94

Answer

$x=-9$ and $x=\dfrac{3}{4}$ satisfy the given conditions

Work Step by Step

$y_{1}=6\Big(\dfrac{2x}{x-3}\Big)^{2}$, $y_{2}=5\Big(\dfrac{2x}{x-3}\Big)$, and $y_{1}$ exceeds $y_{2}$ by $6$ If $y_{1}$ exceeds $y_{2}$ by $6$, then $y_{2}+6=y_{1}$ and $y_{1}-y_{2}=6$ If $y_{1}-y_{2}=6$, then $6\Big(\dfrac{2x}{x-3}\Big)^{2}-5\Big(\dfrac{2x}{x-3}\Big)$ is also equal to $6$: $6\Big(\dfrac{2x}{x-3}\Big)^{2}-5\Big(\dfrac{2x}{x-3}\Big)=6$ Evaluate all operations indicated on the left side: $6\Big[\dfrac{4x^{2}}{(x-3)^{2}}\Big]-\dfrac{10x}{x-3}=6$ $\dfrac{24x^{2}}{(x-3)^{2}}-\dfrac{10x}{x-3}=6$ Multiply the whole equation by $(x-3)^{2}$ $(x-3)^{2}\Big[\dfrac{24x^{2}}{(x-3)^{2}}-\dfrac{10x}{x-3}=6\Big]$ $24x^{2}-10x(x-3)=6(x-3)^{2}$ Evaluate all indicated operations: $24x^{2}-10x^{2}+30x=6(x^{2}-6x+9)$ $24x^{2}-10x^{2}+30x=6x^{2}-36x+54$ Take all terms to the left side of the equation and simplify: $24x^{2}-10x^{2}+30x-6x^{2}+36x-54=0$ $8x^{2}+66x-54=0$ Solve by factoring: $2(x+9)(4x-3)=0$ Take the $2$ to divide the right side: $(x+9)(4x-3)=\dfrac{0}{2}$ $(x+9)(4x-3)=0$ Set both factors equal to $0$ and solve each individual equation for $x$: $x+9=0$ $x=-9$ $4x-3=0$ $4x=3$ $x=\dfrac{3}{4}$ $x=-9$ and $x=\dfrac{3}{4}$ satisfy the given conditions
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.