Question

Solve x2 + 9x + 20 = 0. x = 2, x = 10 x = −2, x = −10 x = −5, x = −4 x = 5, x = 4

Answer 1

x=4 x=5

Explanation:

Answer 2

x^2+9x+20= 0

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

x+4= 0

Move +4 to other side. Sign changes from +4 to -4.

x+4-4= 0-4

x= -4

x+5= 0

Move +5 to other side. Sign changes from +5 to -5.

x+5-5= 0-5

x= -5

Answer : x= -5, x= -4