To evaluate the expression \( \frac{x}{2y} \) when \( x = 8 \) and \( y = 1 \):
- Substitute the values of \( x \) and \( y \) into the expression:
\[ \frac{8}{2 \cdot 1} \]
- Calculate the denominator:
\[ 2 \cdot 1 = 2 \]
- Now, substitute back into the expression:
\[ \frac{8}{2} = 4 \]
So, the value of the expression when \( x = 8 \) and \( y = 1 \) is 4.