Final answer:
To calculate how long it will take Diana to drive to Tony's house at an average speed of x mph, divide the distance to Tony's house by x. Without the distance, we cannot provide a numerical answer.
Step-by-step explanation:
The question asks about the time it would take for Diana to drive to Tony's house at an average speed of x miles per hour (mph). To calculate this, we would need to know the distance to Tony's house. However, using the formula for time: Time = Distance / Speed, we can say that if the distance to Tony's house is d miles, it would take Diana d / x hours to get there. This is based on the idea that average speed is the total distance traveled divided by the total time taken. For example, if the distance was 60 miles and Diana drove at an average rate of 30 mph, it would take her 2 hours to reach Tony's house (60 miles / 30 mph = 2 hours).