(5x^3-7x^3y+3x^2y)+2x^3-(－7x^3y+3x^2y+7x^3)
问题描述：
(5x^3-7x^3y+3x^2y)+2x^3-(－7x^3y+3x^2y+7x^3)
的值与字母x、y的取值无关
答
(5x^3-7x^3y+3x^2y)+2x^3-(－7x^3y+3x^2y+7x^3)=5x^3-7x^3y+3x^2y+2x^3+7x^3y-3x^2y-7x^3=5x^3+2x^3-7x^3+7x^3y-7x^3y+3x^2y-3x^2y=(5+2-7)x^3+(7-7)x^3y+(3-3)x^2y=0*x^3+0*x^3y+0*x^2y=0所以(5x^3-7x^3y+3x^2y)+2x...