Can you please also show me the steps you did to get that answer

Find the unit price for each price.
[tex] Unit\ Price = \frac{Price}{Amount} [/tex]
Divide each price by the amount.
[tex] 6-pack = \frac{3.79}{6} = \$0.63 [/tex]
[tex] 9-pack = \frac{4.50}{9} = \$0.50 [/tex]
[tex] 12-pack = \frac{6.89}{12} = \$0.57 [/tex]
The 9-pack package costs the least per bottle