七年级因式分解题,要过程.

题目

七年级因式分解题,要过程.
1.x²(y²-9)+4(9-y²)
2.(x-2y)²-3(x-2y)-10
3.6(x^n+1)+5(x^n)y-4(x^n-1)y²
4.9-a²-b²+2ab
5.x²-2xy+y²+4x-4y+4
6.(x+y)²-4(x+y+-1)
7.(ax+by)²+(bx-ay)²
8.(c-a)²-4(b-c)(a-b)

答案

1.x2(y2-9)+4(9-y2)=(y2-9)(x2-4)=(y+3)(y-3)（x+2）(x-2)2.(x-2y)2-3(x-2y)-10=(x-2y-5)(x-2y+2)3.6(x^n+1)+5(x^n)y-4(x^n-1)y2=(x^n-1)(6x^2+5xy-4y^2)=(x^n-1)*(2x-y)(3x+4y)4.9-a2-b2+2ab=9-(a-b)2=(3-a+b)(3+a-...