Answer
[tex]\frac{ba-b^{2} }{ab-a^{2} }[/tex]
Step-by-step explanation:
[tex]\frac{1-\frac{b}{a} }{1-\frac{a}{b} } = \frac{\frac{a-b}{a}}{\frac{b-a}{b}} = \frac{b(a-b)}{a(b-a)}[/tex]
[tex]\frac{ba -b^{2} }{ab-a^{2} }[/tex]
