Points on two lines - simultaneous equations

You can move the points using the slider. Two lines only meet at one point. When they meet the solution for each equation is the same i.e. the values for x and y are the both the same. For any other value of x the values for y are different for each equation.
You can change the equations by typing new equations into the Input box - but you must type it as in the examples below. To input x - y = 5 and 2x + y = 6 you type a:x - y = 5 and press enter on the keyboard and b:2x + y = 6 and press enter on the keyboard