-(x+1)²+9(x-2)²因式分解

问题描述:

-(x+1)²+9(x-2)²
因式分解


-(x+1)²+9(x-2)²
=[3(x-2)]²-(x+1)²
=[3(x-2)+(x+1)][3(x-2)-(x+1)]
=(3x-6+x+1)(3x-6-x-1)
=(4x-5)(2x-7)