1. 3(9) is the same as 3×9 so its 3(9)+15 = 42.
2. I want you to do number 2 for me and let me know what you get because its the same as 1 it just has more numbers. I know what it is I just want to see if you understand.
3. For this one its the same as all of them instead you do division. So 56÷4+3(3). Now when you get a problem like this remember to use PEMDAS. If you don't know what that is please look it up it'll help you. First you want to do 3(3) which is 9 and do 56÷4 which is 14. Now you just add those two numbers 14 and 9 to get 23.
