Hey there! I'm happy to help!
Let's represent everybody with variables. Raina is R, Justin is J, and Cho is C. Let's write down this information as a system of equations.
R+J+C=79 (they all have 79 total dollars in their wallets combined)
R=J-5 (Raina has five less than Justin.)
C= 2J (Cho has twice that of Justin)
Since we know what R and C equal, we can plug in their values in terms of J into the first equation to solve for J.
J-5+J+2J=79
We combine like terms.
4J-5=79
We add 5 to both sides.
4J=84
We divide both sides by 4.
J=21
This means that Justin has $21. If Raina has 5 less, she has $16 and since Cho has twice that of Justin he has $42. These added up equal 79.
I hope that this helps! Have a wonderful day!
