\(q = p(r+s) \\ \mbox{divide both sides by }(r+s) \\ p = \dfrac{q}{r+s}\)
\(\mbox{for (2) you don't say what variable to solve for. I'm going to guess }x. \\ a x + z = a w + y \\ a x = a w + y - z \\ x = \dfrac {a w + y - z}{a}\)
\(q = p(r+s) \\ \mbox{divide both sides by }(r+s) \\ p = \dfrac{q}{r+s}\)
\(\mbox{for (2) you don't say what variable to solve for. I'm going to guess }x. \\ a x + z = a w + y \\ a x = a w + y - z \\ x = \dfrac {a w + y - z}{a}\)