Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
Algebra 1 problem help:Completing the sqaure?
Solve x^2+7x=120 by completing the square, please show your work?
Thank you!
2 Answers
- sepiaLv 74 years agoFavorite Answer
x^2 + 7x = 120
(x + 7/2)^2 - 529/4 = 0
(x + 7/2)^2 = 529/4
x + 3.5 = +/- 11.5
Solutions:
x = -15
x = 8
- SqdancefanLv 74 years ago
Half the x-coefficient is 3.5, so we add the square of that to both sides. Then rearrange.
.. x^2 +7x +3.5^2 = 120 +3.5^2
.. (x +3.5)^2 = 132.25
.. x +3.5 = ±11.5 . . . . . . . . take the square root of both sides
.. x = -3.5 ± 11.5 . . . . . . . . add -3.5
.. x = {-15, -8}
