For the first, it starts at the origin, so just remember, .
In this case, the first equation is .
In the second, it leaves 15 minutes later, i.e. 0.25 of an hour later.
So point 1 is .
If it travels at 40miles/hour, then .
Plug them all into the equation to get c. (in this case, y = d = 0, x = t= 0.25, m = v = 40).
You should find that
So the second equation is .
Therefore the system of equations is
Can you solve them to see where they meet?