(x-y)乘(x-y)的三次方乘(x-y)的m次方=(x-y)的12次方(x-y)的(1+3+m)次方=(x-y)的12次方.(x-y)的(4+m)次方=(x-y)的12次方4+m=12m=8,（4m的二次方+2m+1）— 2（2m的二次方-m-5）?=4m²+2m+1-4m²+2m+10=4m+11=4...