It cost $9 to go to pete's Pottery place to make your own bowls for $3 per bowl. Natalie goes to Pete's Pottery place and makes b bowls. She decides to make bowls 5 days this month so she can sell them at a craft fair.

Part A: Write an expression that will represent Natalie's total cost for this month.

Part B: If she makes 4 bowls each time she goes to Pete's Pottery place, what will her total cost be?