To write the equation for the total cost \( y \) in terms of the number of kites purchased \( x \) for Windy Kites, we need to consider both the price per kite and the flat shipping fee.
- The cost per kite is $4, so for \( x \) kites, the cost would be \( 4x \).
- There is a flat rate shipping fee of $16.
Combining these two components, the total cost \( y \) can be expressed as:
\[ y = 4x + 16 \]
This equation gives the total cost \( y \) based on the number of kites \( x \) purchased.