How do you write this in numerical expression and in a answer statement

To write this as a numerical expression, you will think of the different parts of the math story that are occurring and put them together in one math statement.  You have 12 books being ordered that are $9 each AND are paying a $15 shipping charge.  This can be written as 12 x $9 + $15.  There are 2 terms here - these are the 2 parts!  Multiply 12 times 9 first to get $108, then you can add the $15 shipping fee.  You can only add units that are the same, so you must multiply first. Your answer statement is a sentence that gives your final answer in a complete sentence.  For example, the total cost of Lannie's order is $123.

Xis -1/2
y is 35/4.

It would take her 20 minutes.