Alright, let's say that Robert is X years old, and Kent is X - 5 Years old, since he is 5 years younger. Since their ages together add up 39 years old, set these values next to one another.
x + x + 5 = 39
Add Like Terms
2x + 5 = 39
Cancel out the 5
2x = 34
Divide by 2
x = 17
With this, x is 17. This means that Robert is 17 years old since his age was x. With Kent he is 13 years old since 17 - 5 = 13.
All you need to do is 4,302 divided by 3. You would get 1434 pounds. I did this in my head. You can split it to get 4,200 divided by 3 + 102 divided by 3. You get 1400 + 34 which is 1434.
