若xy=1,x-2y=3,-6x^2y+12xy^2=多少?再加说明,
问题描述:
若xy=1,x-2y=3,-6x^2y+12xy^2=多少?再加说明,
答
提出-6xy,原式=-6xy(x-2y)=-6*1*3=-18
若xy=1,x-2y=3,-6x^2y+12xy^2=多少?再加说明,
提出-6xy,原式=-6xy(x-2y)=-6*1*3=-18