Jessica has 9 kess dollars than daniel. altogether, jessica and daniel have 31 dollars. how much money does jessica have?

D= Daniel
J= Jessica

D + J = 31
D + (D-9) = 31
Jessica has 9 less than Daniel, so you have to subtract 9 from the amount Daniel has.
2D - 9 = 31
add 9 to both sides
2D=40
divide both sides by 2
D=20
J = D-9 = 20-9 = 11

To check your answer, add Daniel's money and Jessica's money and it should equal their total amount of money.

20 + 11 = 31

Hope this helps!!  :)