Big Ideas Math - Algebra 1, A Common Core Curriculum

Published by Big Ideas Learning LLC
ISBN 10: 978-1-60840-838-2
ISBN 13: 978-1-60840-838-2

Chapter 9 - Solving Quadratic Equations - 9.6 - Solving Nonlinear Systems of Equations - Exercises - Page 530: 21

Answer

The solutions are $(0,2)$ and $(-6,-22)$.

Work Step by Step

The given system is $y=-x^2-2x+2$ ...... (1) $y=4x+2$ ...... (2) Subtract equation (2) from equation (1). $\Rightarrow y-y=-x^2-2x+2-(4x+2)$ $\Rightarrow y-y=-x^2-2x+2-4x-2$ Simplify. $\Rightarrow 0=-x^2-6x$ Factor out $-x$ from each side. $\Rightarrow 0=-x(x+6)$ Use zero product property. $\Rightarrow -x=0$ or $x+6=0$ Solve for $x$. $\Rightarrow x=0$ or $x=-6$ Substitute $0$ for $x$ in equation (2). $\Rightarrow y=4(0)+2$ Simplify. $\Rightarrow y=2$ Substitute $-6$ for $x$ in equation (2). $\Rightarrow y=4(-6)+2$ Simplify. $\Rightarrow y=-24+2$ $\Rightarrow y=-22$ Hence, the solutions are $(0,2)$ and $(-6,-22)$.
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.