1/2(x-1/2(x-1)-1+2)=2/3(x-1) {将“+1”变为“-1+2”}1/2((x-1)-1/2(x-1)+2)=2/3(x-1) → 1/2(1/2(x-1)+2)=2/3(x-1)1/4(x-1)+1=2/3(x-1) {去括号}5/12(x-1)=1 {移项,合并同类项}x-1=12/5x=17/5=3.4...