Answer:
The system of equations is
and
Fred's age is 36 years old and Nathan's age is 9 years old
Explanation:
Let
f -----> Fred's age
n ----> Nathan's age
we know that
-----> equation A
----> equation B
equate the equations and solve for n

Find the value of f

therefore
Fred's age is 36 years old and Nathan's age is 9 years old