9514 1404 393
Answer:
 Dylan, 61; Ricardo, 57; Trevor, 122; Michael, 308.
Step-by-step explanation:
Let d represent the number of points that Dylan scored. Ricardo scored d-4; Trevor scored 2d; Michael scored 5d+3. Then the total of scores is ...
 total = Dylan + Ricardo + Trevor + Michael
 548 = d + (d-4) + (2d) + (5d+3)
 549 = 9d
 61 = d
Dylan scored 61 points.
Ricardo scored 57 points. Â = 61 -4
Trevor scored 122 points. Â = 2(61)
Michael scored 308 points. Â = 5(61) +3