Explanation:

Let’s break down the math step by step:

- The expression is: 34 + 16 - a × [40 ÷ 5 - 3] - 15

- First, solve inside the brackets:

- 40 ÷ 5 = 8

- 8 - 3 = 5

- So, we have: 34 + 16 - a × 5 - 15

- Combine constants: 34 + 16 = 50

- 50 - 15 = 35

- So now: 35 - a × 5

Now, let's check each option (assuming the question is asking what value of "a" makes the given options correct):

- Option 1: 1 ? 35 - 5×a = 1 ? a = (35-1)/5 = 6.8 — Not an integer

- Option 2: 7 ? 35 - 5×a = 7 ? a = (35-7)/5 = 28/5 = 5.6 — Not an integer

- Option 3: 9 ? 35 - 5×a = 9 ? a = (35-9)/5 = 26/5 = 5.2 — Not an integer

- Option 4: 6 ? 35 - 5×a = 6 ? a = (35-6)/5 = 29/5 = 5.8 — Not an integer

But here's the thing: Unless "a" is a decimal, none of these are perfect fits for an integer "a", but if the question is just asking for the value of the expression as written (with a missing "a") and listing the result for some value, it would depend on what's intended. But with this calculation, none of the options yield a round integer value for "a", but following the calculation as per your answer: