Question

rút gọn biểu thức : ( x+ 2)^3 - 2(x^2 + 6x - 5 ) - 8

Answer 1

\(\left(x+2\right)^3-2\left(x^2+6x-5\right)-8\)

\(=x^3+6x^2+12x+8-2x^2-12x+10-8\)

\(=x^3+4x^2+10\)