一个多项式与单项式-2x²y的积是x²y-1/2x²y²,求此多项式.

一个多项式与单项式-2x²y的积是x²y-1/2x²y²,求此多项式.
一个多项式与单项式-2x²y的积是x²y-1/2x²y²,求此多项式.

一个多项式与单项式-2x²y的积是x²y-1/2x²y²,求此多项式.
x²y-1/2x²y²/（-2x²y）
=x²y(1-1/2y)/(-2x²y)
=-1/2(1-1/2y)
=-1/2+1/4y

(x²y-1/2x²y²)÷(-2x²y)=-1/2+y
∴此多项式是y-1/2