Question 67820
Try this!
Let L = the amount that Luke has and S = the amount that Sam has. From the problem description, you can write:
L = S+$5 and 
L+S = $73  Substitute here the L from above and solve for S.
(S+$5) + S = $73 Simplify.
2S+$5 = $73 Subtract $5 from both sides.
2S = $68  Divide both sides by 2.
S = $34
L = S+$5
L = $39