Algebra help

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 $\frac{\frac{5q}{6}-q}{q-r}.$