Algebra 2 (1st Edition)

Published by McDougal Littell
ISBN 10: 0618595414
ISBN 13: 978-0-61859-541-9

Chapter 4 Quadratic Functions and Factoring - 4.7 Complete the Square - 4.7 Exercises - Skill Practice - Page 288: 28


The solutions are $-4+\sqrt{10}$ and $-4-\sqrt{10}$.

Work Step by Step

$ 2k^{2}+16k=-12\qquad$ ...divide each side with 2 $ k^{2}+8k=-6\qquad$ ...square half the coefficient of $k$. $(\displaystyle \frac{8}{2})^{2}=(4)^{2}=16\qquad$ ...add $16$ to each side of the expression $ k^{2}+8k+16=-6+16\qquad$ ...simplify. $ k^{2}+8k+16=10\qquad$ ... write left side as a binomial squared. $(k+4)^{2}=10\qquad$ ...take square roots of each side. $ k+4=\pm\sqrt{10}\qquad$ ...add $-4$ to each side. $ k+4-4=\pm\sqrt{10}-4\qquad$ ...simplify. $k=-4\pm\sqrt{10}$
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.