几道因式分解的题（初中）x²-xy-30y²=x五次方-x³y²-12xy四次方=7p²-5pq-2q²=6x²-5xy-6y²=30a²-ab-b²=不好意思~还有个：（ax+by）²+（bx-ay）²=

都是交叉相乘,很简单
1. x²-xy-30y²=(x+5y)(x-6y)
2.x五次方-x³y²-12xy四次方
=x(x四次方-x²y²-12y四次方)
=x(x²+3y²)(x²-4y²)
=x(x+2y)(x-2y)(x²+3y²)
3.7p²-5pq-2q²
=(7p+2q)(p-q)
4.6x²-5xy-6y²
=(2x-3y)(3x+2y)
5.30a²-ab-b²
=(6a+b)(5a-b)

x²-xy-30y²
=(x+5y)(x-6y)
x五次方-x³y²-12xy四次方
=x(x四次方-x²y²-12y四次方)
=x(x²+3y²)(x²-4y²)
=x(x+2y)(x-2y)(x²+3y²)
7p²-5pq-2q²
=(p-q)(7p+2q)
6x²-5xy-6y²
=(2x-3y)(3x+2y)
30a²-ab-b²
= (5a-b)(6a+b)

1.x²-xy-30y²=(x+5y)(x-6y)2 x^5-x³y²-12xy^4=x(x^4-x^2y^2-12y^4)=x(x^2+3y^2)(x^2-4y^2)=x(x+2y)(x-2y)(x²+3y²)3.7p²-5pq-2q²=(7p+2q)(p-q)4.6x²-5xy-6y²=(2x-...

x²-xy-30y²
=(x+5y)(x-6y)
x^5-x³y²-12xy^4
=x(x^4-x^2y^2-12y^4)
=x(x^2+3y^2)(x^2-4y^2)
7p²-5pq-2q²
=(7p+2q)(p-q)
6x²-5xy-6y²
=(2x-3y)(3x+2y)
30a²-ab-b²
=(6a+b)(5a-b)