[tex] \dfrac{1 + \frac{1}{y}}{1 - \frac{1}{y}} = [/tex]
[tex] = \dfrac{y}{y} \times \dfrac{1 + \frac{1}{y}}{1 - \frac{1}{y}} [/tex]
[tex] = \dfrac{1 \times y + \frac{1}{y} \times y}{1 \times y- \frac{1}{y} \times y} [/tex]
[tex] = \dfrac{y + 1}{y- 1} [/tex]
Answer: B. [tex] \dfrac{y + 1}{y- 1} [/tex]