Explanation:

Let's solve the equation:

1. Calculate each square:

- \(34^2 = 1156\)

- \(25^2 = 625\)

- \(18^2 = 324\)

- \(9^2 = 81\)

- \(15^2 = 225\)

2. Substitute and simplify:

- The left side of the equation is: \(1156 - 625 + 324 - 81 = 774\)

3. Set the equation:

- \(774 = ? - 225\)

4. Solve for the question mark:

- \(? = 774 + 225 = 999\)

5. Review options:

- Option 1: 991

- Option 2: 999

- Option 3: 899

- Option 4: 1099

- Option 5: 1199

- Result: Option 2: 999 is the correct answer.