Answer:

Explanation:
This question is about order of operations. It stands for parenthesis, exponent, multiply, divide, add, and subtract from left to right.
First thing you do is parenthesis.
![\displaystyle [2-6]=-4](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ayim7egv3486gbmoyhqazx1zmb6izsq3mu.png)
![\displaystyle -4-[-24]](https://img.qammunity.org/2020/formulas/mathematics/middle-school/bpmh3xqqu4mth8mzn5dvdulhcp4liwuyg6.png)
Then, add and subtract numbers from left to right to find the answer.
![\displaystyle -4-[-24]](https://img.qammunity.org/2020/formulas/mathematics/middle-school/bpmh3xqqu4mth8mzn5dvdulhcp4liwuyg6.png)
![\displaystyle -4-[-24]=-4+24=20](https://img.qammunity.org/2020/formulas/mathematics/middle-school/skg49qqsushyyg49kr60np1uirztwmyhfl.png)
20, which is our answer.
Hope this helps!