Problem
ALG-B1-M12-P024 Variant 6, Problem 4
#24
★★★★☆ Level 4 of 5
Find linear \(f\) if \(f(x+y)=f(x)+f(y)+4\).
Let \(f=ax+b\).
\(b=2b+4\), so \(b=-4\). Answer: \(f(x)=ax-4\).
Mock olympiad problem. Tags: linear-functions.