How do you solve abs(x^2+6x)= 3x+18?

1 Answer
Jun 8, 2018

x_1=x_2=-6, x_3=-3 and x_4=3

Explanation:

|x^2+6x|=3x+18

(x^2+6x)^2=(3x+18)^2

(x*(x+6))^2=(3*(x+6))^2

x^2*(x+6)^2=9*(x+6)^2

(x^2-9)*(x+6)^2=0

(x+6)^2(x+3)(x-3)=0

So x_1=x_2=-6, x_3=-3 and x_4=3