Question

已知f((x+2)/x)=x*3+1求f(x)的解析式

Answer 1

f((x+2)/x)=x*3+1

用Y代替x+2)/x),则X=（2/(Y-1)）

则 F(Y)=(2/(Y-1))*3+1=)=(6/(Y-1))+1

即f(X)=(6/(X-1))+1