十字相乘法分解因式 (a²-3a)²-2(a²-3a)-8
问题描述:
十字相乘法分解因式 (a²-3a)²-2(a²-3a)-8
答
(a²-3a)²-2(a²-3a)-8
=(a²-3a-4)(a²-3a+2)
=(a-4)(a+1)(a-2)(a-1)x²-2xy+y²-7x+7y+10 呢x²-2xy+y²-7x+7y+10=(x-y)^2-7(x-y)+10=(x-y+5)(x-y+2)