All the answers of question 2 and question 5

Brackets may seem complicated, but don't worry, they aren't. The bracket just means that you need to distribute the number outside of it to the numbers inside. This will get rid of the bracket. Let's take your first question on number 2 for example. 2(y-8) You need to multiply the two to both numbers inside because they cannot be subtracted first by the rules of PEMDAS, because there is a variable. 2 times y is 2y, and 2 times negative 8 is -16 (The negative sign will always stay with a number) so your answer to 2a is 2y-16.

Same rule applies to the questions on part 5. 3(a+5) + 2a. You need to do what is in the parenthesis first, because of PEMDAS which tells you what part of a multi-step equation needs to be done first. But, since you cannot add five to a, since it is a variable, you move on to the second part of the equation which would be multiplying what is in the parenthesis by 3. 3 times a is 3a, and 3 times 5 is 15. Now your equation should look like this: 3a + 15 + 2a. You can simplify this, because you have two a values. They can be added together. 3a plus 2a is 5a, (the 2a is positive because it has an addition sign in front of it) and your final equation for question 5, part a should be 5a + 15.

I can't answer all of them, but I hope this helps, stranger :)