lim(x→∞）[（2x+3）/（2x-1）]^（x+1）
=lim(x→∞）[1+4/（2x-1）]^（x+1)
=lim(x→∞）[1+4/（2x-1）]^[（2x-1)/4]*[4*（x+1)/（2x-1)]
=lim(x→∞）e^[4*（x+1)/（2x-1)]
=e^2