Answer:
after you compute the total costs per store, you should purchase the computer screens from the first store
Step-by-step explanation:
the total cost for the first store = $629.99 (including freight) - $20 (discount coupon) = $609.99
the total cost for the second store = $579.49 (computer screens) + $39.99 (freight) = $619.48
after you compute the total costs per store, you should purchase the computer screens from the first store