Answer:
[tex] m = - \frac{ \frac{t}{b} + \frac{t}{r} }{1 - \frac{1}{v} } [/tex]
Step-by-step explanation:
[tex] \frac{m}{v} - \frac{t}{b} = m - \frac{t}{r} \\ \frac{m}{v} - \frac{t}{b} + \frac{t}{r} = m \\ - \frac{t}{b} + \frac{t}{r} = m - \frac{m}{v} \\ - \frac{t}{b} + \frac{t}{r} = m(1 - \frac{1}{v} ) \\ - \frac{t}{b} + \frac{t}{r} = \frac{m( 1 - \frac{1}{v}) }{(1 - \frac{1}{v}) } \\ - \frac{ \frac{t}{b} + \frac{t}{r} }{1 - ( \frac{1}{v} ) } = m[/tex]
