A race! Oh, don't forget to stretch guys. Parallel lines always stay the same distance apart, so they will never cross, no matter how long they go on for. And that's why they're used in races. Ready ...
Two lines have equations \(y = {m_1}x + 3\) and \(y = {m_2}x - 7\). If the lines are parallel then \({m_1} = {m_2}\) and if \({m_1} = {m_2}\) then the lines are ...