(11-y-1/7y)x40%+36%y+1/7yx35%=11x38.5% (x为乘号,y为未知数）

★★★ 1/7y是(1/7)y还是1/(7y)；电脑打出来的这种形式请多加一个括号.
(11-y-1/7y)x40%+36%y+1/7yx35%=11x38.5%7/1y都是（7/1）y★白天有点事，做晚了。
(11-y-1/7y)x40%+36%y+1/7yx35%=11x38.5%
去%，两边×100得：40(11-8/7y)+36y+5y=11×38.5
去括号,等等得：440- 320/7y+41y=423.5
合并数字项得：- 320/7y+41y =-16.5
去分母，两边×(-7)得：320y-287y=115.5
合并y项得：33y=115.5
两边÷33得：y=3.5