Question

What are the solving steps and two

solutions to this equation using the quadratic formula?


-x^2-10x-21=0

Answer 1

7 and 3

Explanation:

-b +/- sqrt(b^2+4ac)/2a

10 +/- sqrt(100-84)/2

10 +/- 4/2

7 and 3

Answer 2

-x² - 10x -21 = 0

x² +10x +21 = 0

x² + 7x + 3x + 21 = 0

x ( x+7) + 3 (x+7) = 0

(x+3) (x+7) = 0

when (x+3) = 0,

x = -3

Again,

(x+7) = 0

x = -7