Algebra

x = -2   -1   0

x=-1 or x=-2

x=-1 or x=-2

Solution: x^2+2x=(x^2+2x)^2+2(x^2+2x)

               x^2+2x=x^4+2(x^2)(2x)+(2x)^2+2x^2+4x

               x^2+2x=x^4+4x^3+6x^2+4x

               0=x^4+4x^3+5x^2+2x

               Dividing everything by x gives: x^3+4x^2+5x+2=0

               Using the rational root theorem, you can check if any of these values make the equation equal to 0: 1, -1, 2, -2

               And -1 and -2 both check out.