因式分解下题

主要根据的是提取相同因子.

1.将因式调整下变为:x²(a-1)-4(a-1)=(x²-4)(a-1)=(x+2)(x-2)(a-1)

2.x(x+y)(x-y-x-y)=-2xy(x+y)

1.
(a-1)(x-2)(x+2)

2.
-2xy(x+y)

1,原式=(a -1 )(x ~2 -4 )注：~表示平方符号2,原式=x (x -y )[(x -y )-(x +y )]

原式=X^2(A-1)-4(A-1)
=(A-1)(X^2-4)
=(A-1)(X+2)(X-2)

原式=X(X+Y)(X-Y-X-Y)
=-2XY(X+Y)

1.原式=(x²-4)(a-1)
=(x+2)(x-2)(a-1)

2.原式=x(x+y)(x-y-x-y)
=-2xy(x+y)