7. Roger owes his father \$15. He borrows another $\mathbf{\$ 2 5}$ from him. What integer represents the balance that he owes his father?
(Example 2)

Step 1 ：Roger owes his father \$15. He borrows another \$25 from him. What integer represents the balance that he owes his father?

Step 2 ：Let's denote the initial amount Roger owes his father as \( initial\_debt = 15 \)

Step 3 ：Roger borrows an additional amount, let's denote this as \( additional\_debt = 25 \)

Step 4 ：We can find the total amount Roger owes his father by adding the initial debt and the additional debt. \( total\_debt = initial\_debt + additional\_debt \)

Step 5 ：Substituting the given values, we get \( total\_debt = 15 + 25 = 40 \)

Step 6 ：So, Roger owes his father a total of \(\boxed{40}\) dollars.