18.7x=7.8(两边同时×10)
187x=78
x=78/187
x=0.417≈0.42
3*0.5+6x=3.3
1.5+6x=3.3
6x=3.3-1.5=1.8
x=1.8/6=0.3
3x+2.7÷3=10.8
3x+0.9=10.8
3x=10.8-0.9
3x=9.9
x=9.9/3
x=3.3
3(x-5)=2.4(两边同时÷3)
x-5=0.8
x=5+08
x=5.8
18.7x=7.8(两边同时×10)
187x=78
x=78/187
x=0.417≈0.42
3*0.5+6x=3.3
1.5+6x=3.3
6x=3.3-1.5=1.8
x=1.8/6=0.3
3x+2.7÷3=10.8
3x+0.9=10.8
3x=10.8-0.9
3x=9.9
x=9.9/3
x=3.3
3(x-5)=2.4(两边同时÷3)
x-5=0.8
x=5+08
x=5.8