Answer:
Nick = 13 years old.
Explanation:
Define the variables:
- Let n = the age of Nick (in years).
- Let w = the age of Will (in years).
Given:
- Nick is 5 years older than Will.
- The sum of their ages is 21.
Create a system of equations with the given information and defined variables:

Substitute the first equation into the second equation and solve for n:






Therefore, Nick is 13 years old.
To find the age of Will, simply substitute the found value of n into the first equation and solve for w:


Therefore, Will is 8 years old.