xy-[x+2y+0.5(x-4)*(y-2)]
问题描述：
xy-[x+2y+0.5(x-4)*(y-2)]
=24
求x*y等于多少
答
xy-[x+2y+(0.5x-2)×(y-2)]=24
xy-[x+2y+0.5xy-x-2y+4]=24
xy-x-2y-0.5xy+x+2y-4=24
xy-0.5xy=24+4
0.5xy=28
xy=56