Answer:
I'm assuming when you say the total of $504 you mean just between Josh and his sister? If so, Josh earned $216 and his sister earned $288
Explanation:
Set each person in terms of X. If Josh's sister earned $93 dollars more than her mom, set the equation as (x+93). Since Josh earned $72 less than his sister, he essentially earned 21 dollars more than his mom (x+21). Add those two equations together and set them equal to $504 dollars. Solve for X and solve each equation individually with your answer to find how much each earned.