(1/2)(x-1)=2-(1/5)(x+2)
(x-1)/2=2-(x+2)/5
5(x-1)=20-2(x+2)
5x-5=20-2x-4
5x-5=16-2x
5x-5-16+2x=0
7x-21=0
x=3
经检验,x=3是原方程的根.