题目定义三角表示3abc3abc3abc,方框表示xz+wyxz+wyxz+wy,则×\times×的结果为( )A.72m2n−45mn272m^{2}n-45mn^{2}72m2n−45mn2B.72m2n+45mn272m^{2}n+45mn^{2}72m2n+45mn2C.24m2n−15mn224m^{2}n-15mn^{2}24m2n−15mn2D.24m2n+15mn224m^{2}n+15mn^{2}24m2n+15mn2知识点:单项式乘多项式章节:数与式 / 整式