take 5.75 and add the 10 dollars to get the total money before having to pay mom
[tex]5.75 + 10 = 15.75[/tex]
divide your answer by 45
[tex]15.75 \div 45 = 0.35[/tex]
now you know how much each muffin costs and how much he has to pay to mom so your equation would be
[tex]profit = 0.35m - 10[/tex]