(a-b)^m+3(b-a)^2(a-b)^m

问题描述:

(a-b)^m+3(b-a)^2(a-b)^m

  (a-b)^m+3(b-a)^2(a-b)^m
=(a-b)^m-3(a-b)^2(a-b)^m
=(a-b)^m-3(a-b)^(m+2)
=(a-b)^m[1-3(a-b)^2]