Intermediate Algebra (6th Edition)

Published by Pearson
ISBN 10: 0321785045
ISBN 13: 978-0-32178-504-6

Chapter 8 - Section 8.3 - Solving Equations by Using Quadratic Methods - Exercise Set - Page 501: 43

Answer

The solutions are $\frac{1}{3}$ and $-\frac{1}{2}$.

Work Step by Step

The given equation can be written as: $(x^{-1})^2-x^{-1}-6=0$ Let $u=x^{-1}$. Rewrite the equation above using $u$ to obtain: $u^2-u-6=0$ Factor the trinomial to obtain: $(u-3)(u+2)=0$ Use the Zero Factor Property by equating each factor to zero, then solve each equation to obtain: \begin{array}{ccc} \\&u-3=0 &\text{or} &u+2=0 \\&u=3 &\text{or} &u=-2 \end{array} Since $u=x^{-1}$, then: \begin{array}{ccc} \\&u=3 &\text{or} &u=-2 \\&x^{-1}=3 &\text{or} &x^{-1}=-2 \\&(x^{-1})^{-1}=3^{-1} &\text{or} &(x^{-1})^{-1}=(-2)^{-1} \\&x=\frac{1}{3} &\text{or} &x=-\frac{1}{2} \end{array} Therefore, the solutions are $\frac{1}{3}$ and $-\frac{1}{2}$.
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.