-a(a-x)(x-b)+ab(a-x)(b-x)的公因式是（ B.-a(a-x)(x-b) ）
A.-a B.-a(a-x)(x-b) C.a(a-x) D.a(x-a)
-8a^3b²+12ab^3c-6a²b
=-2ab(4a²b-6b²c+3a)
(x²-2x)(x²-2x+2)+1
=(x²-2x)²+2(x²-2x)+1
=(x²-2x+1)²
=(x-1)^4
(2a²+7a+2)²-16
=(2a²+7a+2+4)(2a²+7a+2-4)
=(2a+3)(a+2)( 2a²+7a-2)