Explanation:

Let's break it down:

- We are given the equation: 17 + 11 - 12 × 36 ÷ 6 = 80

- We should interchange two signs and two numbers from the options to make this equation true.

Analysis of options:

Option 1: x and - ; 17 and 11

- Interchanging x and - changes multiplication to subtraction and vice versa.

- Swap 17 and 11. But even with these changes, reaching 80 is unlikely.

Option 2: + and - ; 6 and 12

- Interchanging + and - flips their roles.

- Swap numbers 6 and 12 in the equation. Still doesn't solve to 80.

Option 3: x and - ; 6 and 12

- Swap multiplication and subtraction, 6 and 12.

- The equation becomes: 17 + 11 × 6 – 36 ÷ 12

- 11 × 6 = 66

- 36 ÷ 12 = 3

- Now: 17 + 66 – 3 = 80

- This option balances the equation.

Option 4: x and - ; 17 and 12

- Swap multiplication and subtraction, and 17 with 12.

- Checking, but the calculation doesn't sum to 80.

Correct Answer: Option 3 – x and - ; 6 and 12