Question

Help meeeee doooo thissss

Answer 1

B: x=-5 and x=4

Explanation:

f(x)= x^2 + x -20

To find the zeros we replace f(x) with 0

`0= x^2 + x -20`

now we solve for x

LEts factor x^2 + x -20

sum is +1 and product is -20

5 * (-4)= -20

5 + (-4) = +1

x^2 + 5x - 4x - 20 = 0

(x^2 + 5x)+(- 4x - 20) = 0

x(x+5) -4 (x+5) = 0

(x-4)(x+5)=0

Set each factor =0 and solve for x

x- 4 =0 so x=4

x+5 =0 so x=-5

x=-5 and x=4