(1)-x²+x²*y² (2)2x平方-12x+18 (3)16(x+y)²-25(x-y)

问题描述:

(1)-x²+x²*y² (2)2x平方-12x+18 (3)16(x+y)²-25(x-y)
(a²+b²)²-4ab(a²+b²)+4a²b²

(1)-x²+x²*y² =x²(y²-1)=x²(y+1)(y-1)(2)2x平方-12x+18 =2(x²-6x+9)=2(x-3)²(3)16(x+y)²-25(x-y)=[4(x+y)+5(x-y)][4(x+y)-5(x-y)]=(...