请高手分解因式：1.（x+y)²-4(x+y-1) 2.(ax+by)²-(bx+ay)²

请高手分解因式：1.（x+y)²-4(x+y-1) 2.(ax+by)²-(bx+ay)²
请高手分解因式：1.（x+y)²-4(x+y-1) 2.(ax+by)²-(bx+ay)²

请高手分解因式：1.（x+y)²-4(x+y-1) 2.(ax+by)²-(bx+ay)²
1.
(x+y)²-4(x+y-1)
=(x+y)²-4(x+y)+4
=(x+y-2)²
2.
(ax+by)²-(bx+ay)²
=(ax)²+(by)²+2abxy- (bx)²-(ay)²-2abxy
=(ax)²-(ay)² - [(bx)²-(by)²]
=a²(x+y(x-y) -b²(x+y(x-y)
=(x+y(x-y)(a+b)(a-b)

1.(x+y-2)^2 2.(ax+by+bx+ay)(ax+by-bx-ay)=(a+b)(x+y)(a-b)(x-y)=(a^2-b^2)(x^2-y^2)

怎么这么难啊

x2y2-4x-4y+4

1.（x+y)²-4(x+y-1)
=(x+y)²-4(x+y)+4
=(x+y-2)²
2.(ax+by)²-(bx+ay)²
=(ax+by+bx+ay)(ax+by-bx-ay)
=(a+b)(x+y)(x-y)(a-b)