Answer:
7/20 mile farther
Explanation:
Subtracting 2/5 mile from 3/4 mile results in the distance you still have to walk:
3/4 - 2/5 = ?
Here the LCD is 20. Thus, 3/4 becomes 15/20 and 2/5 becomes 8/20.
Then 3/4 - 2/5 = 15/20 - 8/20, or 7/20.
You still have 7/20 mile to walk to get home.