Answer:
The required expression that will represent Natalie total costs for this month is
.
Her total cost be $105.
Explanation:
Consider the provided information.
Part (A)
It costs $9 to go to Pete's pottery place to make your own bowls for $3 per bowl.
Let x is the total monthly cost and "b" is the number of bowls she made.
So, the total cost for one day is

She decided to make 5 days this month so she can sell them at a crafts fair.
Thus the Natalie total costs for this month is:

Thus, the required expression that will represent Natalie total costs for this month is
.
Part (B)
Now, we need to calculate her total cost if she makes 4 bowls each time.
Substitute b=4 in the





Hence, her total cost be $105.