Answer:
25 - n
Step-by-step explanation:
n is a variable. It can represent any number. For example, 5 years ago, Mario would be 20 years old since 25-5 is 20.
So, if n is 8, you have to do 25 - 8 to find the answer to how old Mario was 8 years ago.
So his age n years ago, is 25 - n.
Hope this helps!
