Ineed to solve this problem -3 + y = 0 i don't know how,

-3 + y = 0
All you need to do is add 3 to both sides so that the -3 cancels out on the left side. Doing this will also leave you with the variable y on the left side.
Final y= 3

-3 + y = 0
All you need to do is add 3 to both sides so that the -3 cancels out on the left side. Doing this will also leave you with the variable y on the left side.
and tell me what you believe the answer is

Answer for 2: his profit would be $2.88 explanation: you have to first multiply 72 and 0.12 together to get $8.64 once you do that you know how much money the shopkeeper made from selling the candy bars individually. so you have to do 8.64-5.76=2.88 hope that ; )answer for 3: yeah i’m sorry i have no idea what number 3 is. i’m sorry i couldn’t with that.

I'm just guessing, but my answer would c. 0 to 300.