Answer:
the appointment was 1 mile away from Alex's house for every minute of driving time at 50 mph.
Explanation:
Let's call the distance from Alex's house to the appointment "d".
If Alex drives 50 mph, he will cover this distance in d/50 hours.
If he leaves 15 minutes (or 0.25 hours) early and drives 40 mph, he will cover the same distance in (d/40) + 0.25 hours.
Since both of these times are the same (since Alex arrives on time), we can set them equal to each other and solve for d:
d/50 = (d/40) + 0.25
Multiplying both sides by 200 (the least common multiple of 50 and 40) to get rid of the denominators, we get:
4d = 5d + 50
Subtracting 4d from both sides, we get:
d = 50
Therefore, the appointment is 50 miles away from Alex's house.
As you mentioned, the equation X/50 = the appointment was __ miles away from Alex house can be used to solve the problem. Plugging in X = 50 gives:
50/50 = 1
So the appointment was 1 mile away from Alex's house for every minute of driving time at 50 mph.