15X+35X-(150+12*15)=(150+15*35)*10%(50/1+40/1)*20+50/1X=1/=分数线

15X+35X-(150+12*15)=(150+15*35)*10% 50x - 330 = 67.5x=7.95(50/1+40/1)*20+50/1X=1 题目写法不对,应为(1/50 + 1/40) * 20 + x/50 = 12/5 + 1/2 + x/50 = 1x/50 = 1/10x=5