Question 888628
Develop the parentheses and send everything on the same side.

x^2 + 4x + 12 = 4x^2 + 16x + 16

0 = 3x^2 + 12x + 4

This is a quadratic equation for which you have a formula. Plug a=3, b=12, c=4 in the quadratic formula.

Answer: x = -2/3 *(3+sqrt(6)) and x = 2/3 * (-3+sqrt(6))