因式分解 (14 20:49:46)

1 (a+x)m+1(b+x)n-1--(a+x)m(b+x)n
=(a+x)m(b+x)n-1 ×[(a+x)-(b+x)]
=(a+x)m(b+x)n-1 (a-b)
2.x2--2xy--8y2--x--14y--6
=(x-4y)(x+2y)+(2x-8y)-3x-6y-6
=(x-4y)(x+2y)+2(x-4y)-3x-6y-6
=(x-4y)(x+2y+2)-3(x+2y+2)
=(x-4y-3)(x+2y+2)
3.(x2--x--3)(x2--x--5)--3
=(x2-x)2-8(x2-x)+15-3
=(x2-x)2-8(x2-x)+12
=(x2-x-2)(x2-x-6)
=(x-2)(x+1)(x-3)(x+2)