x>1,
y=2+3x+ 4/x-1
= 3x-3 + 4/x-1 +5
=3(x-1)+4/(x-1)+5,
根据均值不等式,
3（x-1)+4/(x-1)>=2√[3(x-1)*4/(x-1)=4√3,
y(min)=4√3+5.