①（11x+y)(11x-y)-(11x+y)²
问题描述：
①（11x+y)(11x-y)-(11x+y)²
答
=(11x+y)(11x-y-11x-y)
=-2y(11x+y)
①（11x+y)(11x-y)-(11x+y)²
=(11x+y)(11x-y-11x-y)
=-2y(11x+y)