3X-1/2{X-1/2(X-1)}=2/3(X-1)
乘以12得
36X-6{X-1/2(X-1)}=8(X-1)
36X-6X+3(X-1)=8X-8
30X+3X-3=8X-8
33X-8X=-8+3
25X=-5
X=-5/25
X=-1/5