I want to know how you do this and can you show the steps so i understand better? Thanks!

In school they say A Positive plus A Positive equals a Positive. So in the first one (+5)+(+8)=+13 Because they are both positives then it’s just simple addition. If it’s subtracting (+5)-(+2)=+3 Since once again they are both positive then it’s simple subtraction. Since you problems are all Positives then just do them how they are addition, subtraction, multiplication, and division. I hope this helps:)

Aand b are correctly balanced reactions. they have the same number of atoms in both sides of the reaction