问题 选择题

一个多项式加上x2y-3xy2得2x2y-xy2,则这个多项式是(  )

A.3x2y-4xy2

B.x2y-4xy2

C.x2y+2xy2

D.-x2y-2xy2

答案

(2x2y-xy2)-(x2y-3xy2

=2x2y-xy2-x2y+3xy2

=x2y+2xy2

故选C.

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