因式分解 3a(x-y)-5b(y-x)a^3b-25ab^3
问题描述：
因式分解 3a(x-y)-5b(y-x)a^3b-25ab^3
答
x，y都是什么值啊？
答
16ax^2-9ay^2
=a(4X+3Y)(4X-3Y)
a(7x+8y)^2-25az^2
=a(7X+8Y+5Z)(7X+8Y-5Z)
3a（a+b）^2-27ab^2
=3a(a+b+3b)(a+b-3b)
=3a(a+4b)(a-2b)
1/8(x-y)^3+8(y-x)
=1/8(X-Y)^3-8(X-Y)
=1/8[(X-Y)^2-64]
=1/8(X-Y+8)(X-Y-8
答
(1) 3a(x--y)--5b(y--x)
=3a(x--y)+5b(x--y)
=(a--y)(3a+5b).
(2) a^3b--25ab^3
=ab(a^2--25b^2)
=ab(a+5b)(a--5b).