Office depot has a sale on school supplies. a spiral notebook costs on $2 and a 3-ring binder costs $5. you need to buy 6 items in order to get the sale prices. you choose a combination of notebooks and binders for a total of $20. in your response, be sure to include: a system of equations to solve the prompt. # spiral notebooks # 3-ring binders if you can solve the problem without writing a system, be sure to communicate your work/thought process so that you can get partial credit.