Given p/q = 5/6, q/r = 7/10, and r/s = 9/4, find
(p - q)/(q - r) and (2q - r)/(r + s)
In each of the equations, manipulate it to get just one variable on one side. Plug the expression back into the expressions.
For example, we know that p/q=5/6. Multiplying boths ides by q, this gives \(p=\frac{5q}{6}\). Plugging this back into \(\frac{p-q}{q-r}\) will give \(\frac{\frac{5q}{6}-q}{q-r}.\)