[23(y-x)^n]乘[25(x-y)^4n]乘[13(x-y)^2n]等于多少?

题目

[23(y-x)^n]乘[25(x-y)^4n]乘[13(x-y)^2n]等于多少?

答案

原式=[2/3(y-x)^n]×[2/5(y-x)^4n]×[1/3)(y-x)^2n]
=(2/3×2/5×1/3)×[(y-x)^n×(y-x)^4n×(y-x)^2n]
=4/45(y-x)^(n+4n+2n)
=4/45(y-x)^7n