化简：x^3+2x^2-4x-8

题目

化简：x^3+2x^2-4x-8

答案

x³+ 2x² - 4x - 8
= (x³+ 2x²) - (4x + 8)
= x²(x + 2) - 4(x + 2)
= (x² - 4)(x + 2)
= (x + 2)(x - 2)(x + 2)
= (x + 2)²(x - 2)