4x-5/6=12
如果是4x-(5/6)=12
则4x=12+5/6=77/6
x=(77/6)÷4=77/24
如果是(4x-5)/6=12
则4x-5=12*6=72
4x=72+5=77
x=77÷4=77/4
8x-3x=15.5
(8-3)x=15.5
5x=15.5
x=15.5÷5=3.1
2.4*x=6*2.5
x=6*2.5÷2.4=25/4