[(3x+4)/(3x-1)]^(x+1)=[1+ 5/(3x-1)]^(x+1)= [1+ 5/(3x-1)]^(x-1/3) * [1+ 5/(3x-1)]^(4/3)
= [1+ 5/(3x-1)]^(4/3) * {[1+ 5/(3x-1)]^[(3x-1)/5)]}^(5/3) =e^(5/3)