Step-by-step explanation:
Let's represent the number of mochas bought with the variable
, and the number of lattes bought with the variable
.
Since there are
students, the total number of mochas and lattes bought must be
. This can be represented with the following equation:

We can also set up another equation based on the total amount spent on the coffe:

If we rearrange the first equation, we can solve for
:

If we substitute this into the second equation, we can solve for
:





Subtituting this back into the original equation, we can solve for
:



Therefore, 9 mochas and 14 lattes were bought.