(x+2)^3-(x-1)^3=9x^2+36

Question

(x+2)^3-(x-1)^3=9x^2+36

Answer 1

(x+2-x+1)*(x^2+4x+4+x^2+x-2+x^2-2x+1) = 9x^2+36

3*(3x^2+3x+3) = 9x^2+36

9x^2+9x+9-9x^2-36=0

9x=27

x=3