(×+2)^3-(×-1)^3=9×^2+36

Question

(×+2)^3-(×-1)^3=9×^2+36

Answer 1

X³+6x²+6х-(х³-3х²+3х-1)=9х²+36
х³+6х²+6х-х³+3х²-3х+1=9х²+36
х³+6х²+6х-х³+3х²-3х-9х²=36-1
3х=35
х=35/3
х=11 2/3