Answer:
The choice A.
Step-by-step explanation:
[tex] \frac{( \frac{a}{b} + 1) }{( \frac{b}{a} - 1) } \\ \\ \\ \frac{( \frac{a}{b} + \frac{b}{b}) }{( \frac{b}{a} - \frac{a}{a}) } = \frac{( \frac{a + b}{b}) }{( \frac{b - a}{a}) } \\ \\ \\ ( \frac{a + b}{b} ) \div ( \frac{b - a}{a} ) \\ \\ \\ (\frac{a + b}{b} ) \times ( \frac{a}{b - a} ) \\ \\ \\ = \frac{a(a + b)}{b(b - a)} [/tex]
I hope I helped you^_^
