5(2+х)^3-5х^3=28х+30х^2

Question

5(2+х)^3-5х^3=28х+30х^2

Answer 1

5(2+х)^3-5х^3=28х+30х^2
5(8+12x+6x²+x³)-5x³=28x+30x²
40+60x+30x²+5x³-5x³=28x+30x²
60x-28x=-40
32x=-40
x=-5/4
x=-1.25