If the sandwich costs x dollars per foot and it is y inches long, what is the cost?
I think this question is about creating an equation.
Let C = cost
Let x = dollar per foot
Let y = amount in inches
C = xy
Is this correct?
If you cancel as many units as possible, then yes, that's what you get, although normally you'd put the units at the end, as in C = xy/12 dollars. If you submitted the answer C = x(dollars)(y/12) I think the teacher would see this as somewhat odd.
Removing all units just results in C = xy/12.