(X-1)*1/9+1=2+{X-1-[(X-1)*1/9+1]-2}*1/9
………………………=…………………………
……………………=……………………
………………=………………
X=?
參考答案:(X-1)*1/9+1=2+{X-1-[(X-1)*1/9+1]-2}*1/9
x/9-1/9+1=2+{x-1-(x-1)*1/9-1-2}*1/9
x/9+8/9=2+[x-x/9+1/9-4]*1/9
x/9+8/9=2+8/81x-35/81
x/9-8/81x=2-35/81-8/9
1/81x=55/81
x=55