x^2 + (x+1)^2 - (x+2)^2 = (x+1)(x+2)
x^2+(x^2+2x+1)-(x^2+4x+4)=x^2+3x+2
x^2+(x^2+2x+1)-(x^2+4x+4)- (x^2+3x+2) = 0
-5x -5 = 0
x = -1
x^2 + (x+1)^2 - (x+2)^2 = (x+1)(x+2)
x^2+(x^2+2x+1)-(x^2+4x+4)=x^2+3x+2
x^2+(x^2+2x+1)-(x^2+4x+4)- (x^2+3x+2) = 0
-5x -5 = 0
x = -1