you are buying orange juice for $4.50 per container and have a gift card worth $7. TheFunction f(x)=4.50x-7 represents your total cost f(x) if you buy x containers of orange juice and use the gift card. How much do you pay to buy 4 containers of orange juice?
Is this correct: f(4)=4.50(4)-7
f(4)=18-7
f(4)=11
so I would pay $11 for 4 containers of orange juice?