初二下的因式分解
(1)(a+b)²-6(a+b)-7=
(2)(x-2)²+5(x-2)+4=
(3)(a-b)²+3(a-b)(a+b)-10(a+b)²=
(4)(x+2y)²-4(x+2y)y-21y²=
(5)(x²+x)²-14(x²+x)+24=
(6)x(x+z)-y(y+z)=