首先,很高兴回答你的问题0.75X+3X0.8=7.50.75X+2.4=7.50.75X=5.1X=6.8所以得出X为6.8 希望采纳,谢谢
0.75x+3*0.8=7.50.75x+2.4=7.50.75x=5.1x=6.8
6.8