2. A subway in the UK is a pedestrian route that goes under a road.
3. Subway is the trade name of a multinational franchising company selling sandwiches and salads.
... expression to the left of "=", that will make it a perfect square trinomial of the form x2 + 2xy + y2. Since "2xy" in this case is (b/a)x, we must have y = b/(2a), so we ...