Question

方程x^3+x^2-8x-8=0 因式分解

Answer 1

x^3+x^2-8x-8=0

x^2(x+1)-8(x+1)=0

(x+1)(x^2-8)=0

(x+1)(x+2√2)(x-2√2)=0

解得x=-1或x=-2√2或x=2√2