Question

Solve x^2+11x=−10 by completing the square.
The solutions are x= ___ and x=___.

Answer 1

-10, -1

Explanation:

To complete the square, we add the square of half the x-coefficient:

x^2 +11x +5.5^2 = -10 +5.5^2

(x +5.5)^2 = 20.25

Taking the square root, we get ...

x +5.5 = ±4.5

x = -5.5 ±4.5 = {-10, -1}

The solutions are x = -10 and x = -1.