(x方+5x+3)平方-2(x方+5x+3)(x方十5x-2)+(x方+5x-2)平方

问题描述:

(x方+5x+3)平方-2(x方+5x+3)(x方十5x-2)+(x方+5x-2)平方

设a=x方+5x+3,b=x方+5x-2,则原式变为
a方-2ab+b方=(a-b)方=[(x方+5x+3)-(x方+5x-2)]方=[3+2]方=25