3x²-4x²y+3xy²-y³-4
=3x²-4-4x²y+3xy²-y³
=﹙3x²-4﹚-﹙4x²y-3xy²+y³﹚
两个多项式是3x²-4和4x²y-3xy²+y³
或
3x²-4x²y+3xy²-y³-4
=-4x²y+3xy²-y³+3x²-4
=﹙-4x²y+3xy²-y³﹚-﹙4-3x²﹚
两个多项式是4-3x²和-4x²y+3xy²-y³
3x²-4x²y+3xy²-y³-4
=3x²-4-4x²y+3xy²-y³
=﹙3x²-4﹚-﹙4x²y-3xy²+y³﹚
两个多项式是3x²-4和4x²y-3xy²+y³
或
3x²-4x²y+3xy²-y³-4
=-4x²y+3xy²-y³+3x²-4
=﹙-4x²y+3xy²-y³﹚-﹙4-3x²﹚
两个多项式是4-3x²和-4x²y+3xy²-y³