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: 12

Answer

The solutions are $(-3,14)$ and $(1,2)$.

Work Step by Step

The given system is $y=4x^2+5x-7$ ...... (1) $y=-3x+5$ ...... (2) Graph each equation. The point of intersections are $A=(-3,14)$ and $B=(1,2)$. Check: $(x,y)=(-3,14)$ Equation (1). $\Rightarrow y=4x^2+5x-7$ $\Rightarrow 14=4(-3)^2+5(-3)-7$ $\Rightarrow 14=36-15-7$ $\Rightarrow 14=36-22$ $\Rightarrow 14=14$ True. Equation (2). $\Rightarrow y=-3x+5$ $\Rightarrow 14=-3(-3)+5$ $\Rightarrow 14=9+5$ $\Rightarrow 14=14$ True. Check: $(x,y)=(1,2)$ Equation (1). $\Rightarrow y=4x^2+5x-7$ $\Rightarrow 2=4(1)^2+5(1)-7$ $\Rightarrow 2=4+5-7$ $\Rightarrow 2=9-7$ $\Rightarrow 2=2$ True. Equation (2). $\Rightarrow y=-3x+5$ $\Rightarrow 2=-3(1)+5$ $\Rightarrow 2=-3+5$ $\Rightarrow 2=2$ True. Hence, the solutions are $(-3,14)$ and $(1,2)$.
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.