Answer:
x=-1
Step-by-step explanation:
x3+x2=-9x-9
add 9x +9 on each side
x^3+x^2+9x+9=-9x-9+9x+9
x^3+x^2+9x+9=0
factor out an x^2 from the left 2 terms and a 9 from the right 2 terms
x^2 (x+1) +9(x+1) = 0
factor out x+1
(x+1) (x^2+9) = 0
using the zero product property
x+1 =0 x^+9 =0
x=-1 x^2 =-9
x=-1 sqrt(x^2) = sqrt(-9)
x=-1 x = ±3i
