Answer
No solution.
Work Step by Step
$(x+8)^2=16-x^2+9x\\x^2+16x+64=16-x^2+9x\\2x^2+7x+48=0\\2(x+1.75)^2+41.875=0$
Since the sum consists of a non-negative expression and a positive term on the left hand side, this is never equal to zero, thus we have no solution.