解: 3x=8.4
x=2.8
3X=8.4
X=2.8
1. 3x=8.4
解:x=2.8
2. 7/x=0.9
解:x=70/9
3. x-42.6=3.4
解:x=46
4. 6x+4*0.7=11.8
解:6x+2.8=11.8
6x=9
x = 1.5 望采纳,very very very very thank you