First, let's initialize a variable called 'h' that will represent the number of hours it took to drive to Disneyland (you could do from if you wanted, in the end it doesn't really matter)
Since we know that the distance there and back is the exact same, we can make the following equation:
50(h) = 40(7.2 - h)
We know we can write this equation because rate multiplied by time is distance. We also know that the time to come back is 7.2 minus h, since h represents the time going there.
Simplify:
5(h) = 4(7.2 - h)
5h = 28.8 - 7h
12h = 28.8
h = 2.4
Now that we have the time it took to drive there, we can simply multiply it by the rate to find distance:
50*2.4 = 120
The distance to Disneyland is 120 miles.
If you need me to explain anything here, just ask :)
-T.B.