From the given problem, there are 3 computer labs and each lab has "s" computer stations.
So the total number of computers is :
Mr. Baxter is ordering a new keyboard and a mouse for each computer, since the cost of a keyboard is $13.50 and the cost of a mouse is $6.50.
Each computer has 1 keyboard and 1 mouse, so the total cost needed for 1 computer is :
Since you now have the cost for 1 computer, multiply this to the total number of computers which is 3s to get the total cost needed by Mr. Brax :
Using distributive property :
Distribute s inside the parenthesis :
One answer is 1st Option 3(13.50s + 6.50s)
Simplifying the expression further :
Another answer is 4th Option 3(20.00s)