Algebra 2 Common Core

Published by Prentice Hall
ISBN 10: 0133186024
ISBN 13: 978-0-13318-602-4

Chapter 4 - Quadratic Functions and Equations - 4-9 Quadratic Systems - Practice and Problem-Solving Exercises - Page 263: 50

Answer

The solution is $(-2, 4)$.

Work Step by Step

We will use substitution to solve this system of equations. We substitute one of the expressions for $y$, which would mean that we are going to set the two equations equal to one another to solve for $x$ first: $x^2 + 3x + 6 = -x + 2$ We want to move all terms to the left side of the equation. $x^2 + 3x + x + 6 - 2 = 0$ Combine like terms: $x^2 + 4x + 4 = 0$ Factor the quadratic equation. The quadratic equation takes the form $ax^2 + bx + c = 0$. We need to find factors whose product is $ac$ but sum up to $b$. In this exercise, $ac = 4$ and $b = 4$. The factors $2$ and $2$ will work: $(x + 2)(x + 2) = 0$ The two factors are the same. Set the factor equal to $0$. $x + 2 = 0$ Subtract $2$ from each side of the equation: $x = -2$ Now that we have the value for $x$, we can plug it into one of the original equations to find the corresponding $y$ value. Let's use the second equation: $y = -x + 2$ Substitute the solution $-2$ for $x$: $y = -(-2) + 2$ Multiply next: $y = 2 + 2$ Add to solve: $y = 4$ The solution is $(-2, 4)$.
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.