College Algebra (6th Edition)

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

Chapter 5 - Systems of Equations and Inequalities - Exercise Set 5.4 - Page 559: 46

Answer

-3 or 3 and -2 or 2

Work Step by Step

We are given the system: $\begin{cases} x^2-y^2=5\\ 3x^2-2y^2=19 \end{cases}$ We will use the addition method. Multiply Equation 1 by -2 and add it to Equation 2 to eliminate $y$ and determine $x$: $\begin{cases} -2x^2+2y^2=-2(5)\\ 3x^2-2y^2=19 \end{cases}$ $-2x^2+2y^2+3x^2-2y^2=-10+19$ $x^2=9$ $x=\pm\sqrt 9$ $x=\pm 3$ $x_1=-3$ $x_2=3$ Substitute each of the values of $x$ in Equation 1 to determine $y$: $x^2-y^2=5$ $x_1=-3\Rightarrow (-3)^2-y^2=5\Rightarrow y^2=4\Rightarrow y_1=-2,y_2=2$ $x_2=3\Rightarrow (3)^2-y^2=5\Rightarrow y^2=4\Rightarrow y_3=-2,y_4=2$ The system's solutions are: $(-3,-2), (-3,2), (3,-2),(3,2)$ The numbers are -3 or 3 and -2 or 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.