单项式-7x^2y,3x^2y^2z,-二分之一xy,5x^2y,0.5xy,-4x^3的和是( )A.五次三项式B.五次四项式C.三次多项式D.
问题描述：
单项式-7x^2y,3x^2y^2z,-二分之一xy,5x^2y,0.5xy,-4x^3的和是( )A.五次三项式B.五次四项式C.三次多项式D.
答
选A
五次三项式
答
-7x^2y+3x^2y^2z+(-二分之一xy)+5x^2y+0.5xy+(-4x^3)
=-7x^2y+3x^2y^2z-0.5xy+5x^2y+0.5xy-4x^3
=-4x^3-2x^2y+3x^2y^2z选A
五次三项式