Let the age of Justin be x years .
And Pyton is three years younger than Justin, therefore Peyton age is
\((x-3)years\)
And Matt is four times as old as Peyton, therefore Matt age is
\(4(x-3) years\)
And it is given that
\(x+x-3+4(x-3)=39\)
\(x+x-3+4x-12=39
\\
6x-15=39 \\
6x=54
\\
x =9 years\)
Therefore , Justin is 9 years old, Peyton is 6 years old and Matt is 24 years old .