Answer:
5.4 days (6 days)
Explanation:
First set up an equation. (x represents days)
5 dollars a day = 5x ; Already has 45 = +45 ; Needs 72 = =72
That means your equation is...
5x + 45 = 72
Now solve for x.
5x = 27 Subtract 45 from both sides.
x = 5.4 Divide both sides by 5.
This means he will have to work for at least 6 days.
I hope this helped. :) (I love these kinds of problems!)