Answer:
Jack - $28
David - $17
Step-by-step explanation:
Jack has 2d-6 where d is David's money. David has d money. Together they have 45 and we add the two together.
2d-6+d=45
3d-6=45
3d=51
d=$17
We can then substitute back and find 2(17)-6=34-6=$28.