Solve this using the quadratic formula

(x+4)^2=15-2x^2

Enter two simplified solutions

simplify
x^2 + 8x + 16 - 15 + 2x^2 = 0
3x^2 +8x + 1 = 0

use quadratic formula
x = [-b +/- sqrt(b^2 - 4ac)]/2a

x = [-8 +/- sqrt(64 - 12)]/6

x = -(4/3) + sqrt(13)/3
and
x = -(4/3) - sqrt(13)/3