Precalculus (6th Edition) Blitzer

Published by Pearson
ISBN 10: 0-13446-914-3
ISBN 13: 978-0-13446-914-0

Chapter 8 - Section 8.1 - Matrix Solutions to Linear Systems - Exercise Set - Page 895: 68

Answer

Solution is, $\left( 0,-2 \right)\text{ and }\left( 8,6 \right)$.

Work Step by Step

Consider the provided system of equations, $x-y=2$ …… (I) ${{y}^{2}}=4x+4$ …… (II) Solve equation (I) for $y$ in terms of $x$ to get, That is, $\begin{align} & x-y=2 \\ & y=x-2 \end{align}$ Now by substituting the value of $y$ obtained above in equation (II), we get, Thus, $\begin{align} & {{\left( x-2 \right)}^{2}}=4x+4 \\ & {{x}^{2}}-4x+4=4x+4 \end{align}$ Add $-4x-4$ on both sides, $\begin{align} & {{x}^{2}}-4x+4-4x-4=4x+2-4x-4 \\ & {{x}^{2}}-8x=0 \\ & x\left( x-8 \right)=0 \end{align}$ This implies: Either $x=0$ or, $x-8=0$, that is, $x=8$ Now, from equation (I), If $x=0$, Then, $\begin{align} & 0-y=2 \\ & y=-2 \end{align}$ If $x=8$ , Then, $\begin{align} & 8-y=2 \\ & y=8-2 \\ & y=6 \end{align}$ Hence, $\left( 0,-2 \right)$ and $\left( 8,6 \right)$ are the solutions of the provided system.
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.