2(1+3x)2\left(1+\frac{3}{x}\right)2(1+x3)
1+32x1+\frac{3}{2 x}1+2x3
2(1+x3)2\left(1+\frac{x}{3}\right)2(1+3x)
1+2x31+\frac{2 x}{3}1+32x