1. The problem asks to find the expression for "5 subtract two fifths of y". 2. We start by identifying the parts: "5" is a constant number, and "two fifths of y" means multiplying $y$ by $\frac{2}{5}$. 3. The expression for "two fifths of y" is $\frac{2}{5}y$. 4. Subtracting this from 5 gives the expression: $$5 - \frac{2}{5}y$$ 5. This is the simplified expression representing the problem statement. Final answer: $$5 - \frac{2}{5}y$$