{(39-3y)/12}+4y=37
=>39-3y+48y=37x12
=>45y=37x12-39
=>15y=37x4-13=148-13=135
=>y=9不好意思啊。题目是3×6分之39-3y+4y=37{(39-3y)/18}+4y=37=>39-3y+72y=37x18=>69y=37x18-39=>23y=37x6-13=222-13=209=>y=209/23