Put your full explanation and make sure it's correct, .

[(10 - 5 * 2) + 20] + 100/10

How you would solve it is to solve parentheses first, then the brackets, then everything else. So 5*2 is 10, then 10-10 is 0. So you have now you just have [0+20]+100/10. So now you have 20+100/10. 20+100 is 120. So now, it's 120/10. You get 12. That is your final answer-12.