1.因式分解下面各式

(1) (x²+4x)²-2(x+2)²-7

(2) (x²-x)²+8(x-x²)+12

(3) 7(x-1)²+4(x-1)(y+2)-20(y+2)²

(4) (xy+1)(x+1)(y+1)+xy

(5) (x²-5x+8)(x²-5x+2)+8