B. they are directly proportional because she keeps taking 3 at a time to his 1 at a time.
-Distribute the number outside the parenthesis into all the numbers within.
-Move the numbers with an "x" attached to it to one side and the numbers without an "x" to the other. be sure to change signs as you do (positive to negative, negative to positive)
-subtract or add the numbers on each side together
-divide the number attached to the "x" on both sides (ex. 7x=14, you divide 7)
- you get your answer (x=......)
I would choose b i hope you get it right