x^2+px+q型的因式分解1.x^2+6x-72 2.x^2-3x-18 3.(x+y)^2-8(x+y)-48 4.x^4-7x^2-18 5.x^2-10xy-56y^2给你们一个公式：x^2+(a+b)x+ab=(x+a)(x+b)

1.(x+12)(x-6)
2.(x-6)(x+3)
3.(x+y-12)(x+y+4)
4.(x^2+2)(x+3)(x-3)
5.(x-14y)(x+4y)

1 (x+12)(x-6)
2 (x-6)(x+3)
3 (x+y-12)(x+y+4)
4 (x^2+2)(x+3)(x-3)
5 (x-14y)(x+4y)

1.x^2+6x-72 =(x-6)(x+12)2.x^2-3x-18 =(x-6)(x+3)3.(x+y)^2-8(x+y)-48 =(x+y-12)(x+y+4)4.x^4-7x^2-18 =(x^2+2)(x^2-9)=(x^2+2)(x+3)(x-3)5.x^2-10xy-56y^2 =(x-14y)(x+4y)

1.........
(x+12)(x-6)
2.......
(x-6)(x+3)
3.........
(x+y-12)(x+y+4)
4..........
(x^2-9)(x^2+2)=(x+3)(x-3)(x^2+2)
5........
(x-14y)(x+4y)