Well the question is asking how many roses and carnations Dan sells each week so:
First you would find out how many roses and carnations he sells in a day which would be 14 roses and 24 carnations. (24-10=12 and 36-12=24)
Now the expression.
X would equal the total amount of roses and carnations Dan sells each week.
It would be written like:
12(7) x 24(7) = X