What is the only solution of 2x2 + 8x = x2 - 16

If you would like to solve the equation 2 * x^2 + 8 * x = x^2 - 16, you can calculate this using the following steps:

2 * x^2 + 8 * x = x^2 - 16

2 * x^2 - x^2 + 8 * x + 16 = 0

x^2 + 8 * x + 16 = 0

(x + 4) * (x + 4) = 0

x = - 4

The correct result would be x = - 4.