Question

Solve the quadratic equation below by factoring: *2 + 9x = -20 O A. x = 4,5 O B. x = 1,9 O C. x = -2,-10 O D. x= -4,-5

Answer 1

x^2 + 9x = -20

Rearrange:

x^2 + 9x - (-20) = 0

x^2 + 9x + 20 = 0

the Equation has the form:

ax^2 + bx +c = 0

Where:

a=1

b= 9

c= 20

Find the sum of 2 numbers that equal b, and multiplied equal c.

4+5= 9 (b)

4x5 =20 (c)

Factor:

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

Equal each equation to zero and solve for x

x+4= 0

x= -4

x+5=0

x=-5

Solution:

x=-4 , x =-5