To determine the amount \( a \) that Mike paid for buying 8 yards of ribbon at a cost of $3.50 per yard, we can set up the equation based on the total cost.
The total cost \( a \) can be represented as follows:
\[ a = \text{(number of yards)} \times \text{(cost per yard)} \]
In this case, Mike bought 8 yards of ribbon at $3.50 per yard:
\[ a = 8 \times 3.50 \]
Now, we can complete the equation that has \( a/8 \):
Starting from \( a = 8 \times 3.50 \), we can divide both sides of this equation by 8:
\[ \frac{a}{8} = 3.50 \]
Now we can calculate the total amount \( a \):
\[ a = 8 \times 3.50 = 28 \]
So, we can fill in the blanks:
- For \( \frac{a}{8} \): 3.50
- For \( a \): 28 dollars
The completed equation is:
\[ \frac{a}{8} = 3.50 \] \[ a = 28 \text{ dollars} \]