Move all terms to one side
2x^2 + 8x - x^2 + 16 = 0
Simplify 2x^2 + 8x - x^2 + 16 to x^2 + 8x + 16
x^2 + 8x + 16 = 0
Rewrite x^2 + 8x + 16 in the form a^2 + 2ab + b^2, where a = x and b = 4
x^2 + 2(x)(4) + 4^2 = 0
Use the Square of Sum: (a + b) = a^2 + 2ab + b^2
(x + 4)^2 = 0
Take the square root of both sides
x + 4 = 0
Subtract 4 from both sides
x = -4
