计算 (x-3)^3+27

问题描述:

计算 (x-3)^3+27

(x-3)^3+27
=(x-3+3)[(x-3)²-3(x-3)+3²]
=x(x²-6x+9-3x+18)
=x(x²-9x+27)
=x³-9x²+27x