Question

Can I have help with this one pls

Answer 1

`r = (a)/(b - pcos( \theta)) \\ \\ r * (b - pcos( \theta)) = \frac{a}{ \cancel{b - pcos( \theta)}} * \cancel{b - pcos( \theta)} \\ \\ a = r * (b - pcos( \theta) \\ \\ a = rb - rpcos( \theta)`