几道因式分解的题（初中）x²-xy-30y²=x五次方-x³y²-12xy四次方

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-3y)(3x+2y)
5.30a²-ab-b²
=(6a+b)(5a-b)
6.（ax+by）²+（bx-ay）²
=a²x²+b²y²+2abxy+b²x²+a²y²-2abxy
=x²(a²+b²)+y²(a²+b²)
=(x²+y²)(a²+b²)

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)

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)...

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)
7p²-5...