Ali's class wants to order 35 English textbooks and 35 geography textbooks. Knowing that a geography book costs $10.50 and that an English book costs $7.50, what is the amount of this order?
The cost of the geography books is 35 * 10.5 = $<T>multiply(35, 10.5)=367.5.
The cost of the English books is 35 * 7.5 = $<T>multiply(35, 7.5)=262.5.
The total amount of the order is 367.5 + 262.5 = $<T>add(367.5, 262.5)=630.0
