Question

求帮忙、因式分解、 6xy^2-9x^2y-y^3= （ a-b）^3（x-y）+（x+y）（a-b）^3= 25（m-n）^2-9b^2（m-n）^2=

Answer 1

6xy^2-9x^2y-y^3
=-y(9x^2-6xy+y^2)
=-y(3x-1)^2

（ a-b）^3（x-y）+（x+y）(a-b)^3
=(a-b)^3(x-y+x+y)
=2x(a-b)^3

25（m-n）^2-9b^2（m-n）^2
=(m-n)^2(25-9b^2)
=(m-n)^2(5+3b)(5-3b)

Answer 2

6xy^2-9x^2y-y^3
=-y(y^2-6xy+9x^2)
=-y(y-3x)^2

（ a-b）^3（x-y）+（x+y）（a-b）^3
=(a-b)^3(x-y+x+y)
=2x(a-b )^3

25（m-n）^2-9b^2（m-n）^2
=(5m-5n-3bm+3bn)(5m-5n+3bm-3bn)