(x-4)/2+(0.2x-0.3)/0.5=0.02x/0.01
两边同时乘于2
(x-4)+4(0.2x-0.3)=200×0.02x
x-4+0.8x-1.2=4x
x+0.8x-4x=4+1.2
-2.2x=5.2
x=-52/22