Problem 4
I recommend to draw a number line. Place the baseball park at 0 on the number line.
Then place Luke's house at -3. The distance from -3 to 0 is 3 units, to represent the 3 miles.
Place Logan's house at 2 on the number line.
To go from -3 to 2, move 5 units to the right. This is the longest distance possible because each person's house is on opposite sides of the baseball park.
To get the shortest distance possible, we'll place each person's house to the right of 0. This time each person's house is on the same side.
We'll move Luke from -3 to +3. Keep Logan at 2. The distance from 2 to 3 is 1 unit. This is the shortest distance possible.
Answers:
Shortest distance = 1 mile
Longest distance = 5 miles
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Problem 5
d = distance between Luke's house and Logan's house
Refer to the result of problem 4, where we found d = 1 the smallest possible value of d. And also d = 5 the largest possible value.
In other words: d is between 1 and 5, including each endpoint.
The compound inequality to set up is

The graph involves closed filled in circles at 1 and 5 on the number line. Shade the region between these endpoints. Closed endpoints visually tell the reader "include this endpoint".
Answers:
Inequality:

Graph: Closed filled in circles at 1 and 5; shading in between
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Problem 6
The largest distance we previously found was 5 miles.
Luke traveled 0.5 miles so far, meaning he has at most 5-0.5 = 4.5 miles left to go.
Answer:
4.5 miles