单项式-3x2减去单项式-4x2y,-5x2,2x2y的和,列算式为_,化简后的结果是_.
问题描述:
单项式-3x2减去单项式-4x2y,-5x2,2x2y的和,列算式为______,化简后的结果是______.
答
根据题意得,算式为:-3x2-[-4x2y+(-5x2)+2x2y],
-3x2-[-4x2y+(-5x2)+2x2y]
=-3x2+4x2y+5x2-2x2y
=2x2+2x2y
=2x2(1+y).