(3X
题目有误吧？应该是(3x-5y)^2-(5y+3x)^2 (3x-5y)^2-(5y+3x)^2 =(3x-5y)^2-(3x+5y)^2 =(3x-5y+3x-5y)(3x-5y-3x-5y) =6x*(-10y)=60x(-y)=60