Explanation:

- Let's start by simplifying the initial equation with no changes:

$12+156÷13\times 6-100=50$.

- Following the order of operations (PEMDAS/BODMAS), we first do the division and multiplication:

- $156÷13=12$

- $12\times 6=72$

- The equation becomes:

$12+72-100$.

- Now, subtract and add:

$12+72=84$

$84-100=-16$

- The result is not 50.

- Option 1: Swap ÷ and ×

- Following order of operations, simplify:

$12+13\times 156÷6-100$.

- $13\times 156=2028$

- $2028÷6=338$

- $12+338-100=250$

- This does not balance as 50.

- Option 2: Swap + and ×

- Equation becomes:

$12\times 156÷13+6-100$.

- $12\times 156=1872$

- $1872÷13=144$

- $144+6-100=50$

- Correct outcome of 50.

- Option 3: Swap - and ×

- Simplify:

$12+156÷13-6\times 100$.

- $156÷13=12$

- $12\times 100=1200$

- $12+12-1200=-1176$

- Doesn’t balance with 50.

- Option 4: Swap ÷ and -

- Equation becomes:

$12+156-13\times 6÷100$.

- Following order of operations:

- $13\times 6=78$

- $78÷100=0.78$

- $12+156-0.78˜167.22$

- Result not equal to 50.