计算3x[xy-2x(1/y-x/3]+3y(x²-y²)

问题描述:

计算3x[xy-2x(1/y-x/3]+3y(x²-y²)

3x[xy-2x(1/y-x/3]+3y(x²-y²)
=3x²y -6x²/y+x²+3x²y-3y3
=6x²y-6x²/y+x²-3y3

原式=3x(xy-2x/y+2x²/3)+3x²y-3y³
=3x²y-6x²/y+2x³+3x²y-3y³
=2x³+6x²y-3y³-6x²/y