Evaluate 15r+6 (60-r) for r = 20,30 and 40. what conclusion can you draw

15 (20) + 6 (60-20) = 240

15 (30) + 6 (60-30) = 630

15 (40) + 6 (60-40) = 720

you can conclude that none of the numbers have anything in common except that they all end in a 0