Answer:
3s+7.99= 71.83 .
Step-by-step explanation:
since there are 3 shirts you would multiply s by 3 so 3s. To me it looks like 7.99 is the constant and 71.83 is the total including this constant. so putting all of these together in y=mx+b format you get the equation 71.83= 3s+7.99
hope this helps
