Carlotta handpaints T-shirts and sells them to her friends. She uses the equations below to determine her costs to produce shirts and the amount of money earned when she sells the shirts. Production Cost: c = 28 + 3 s, where c is the total cost and s is the number of shirts Money Earned: m = 10 s, where m is the amount of money earned from sales and s is the number of shirts How many shirts must Carlotta sell to make a profit?