3xy[2xy-3(xy-1/2x^2y)]

问题描述:

3xy[2xy-3(xy-1/2x^2y)]

3xy[2xy-3(xy-1/2x^2y)]
=3xy[2xy-3xy+3/2x^2y]
=3xy[-xy+3/2x^2y]
=-3x^2y^2+9/2x^3y^2哦亲,在详细一点吧...我看不懂啊