Answer:
[tex]\fbox{\begin{minipage}{15em}A half-liter of water costs 2.46$\end{minipage}}[/tex]
Step-by-step explanation:
Dominique wants to buy [tex]2[/tex] liters of water.
Case 1:
A half-liter of water costs [tex]2.46[/tex].
The [tex]2[/tex] half-liters is [tex]1[/tex] liter => The cost of a liter of water ([tex]A[/tex]) is calculated by multiply the cost of [tex]1[/tex] half-liter by [tex]2[/tex]:
[tex]A = 2.46[/tex] x [tex]2[/tex] = [tex]4.92[/tex]
=> The cost of two liters: [tex]A_{1}[/tex] = [tex]A[/tex] x [tex]2[/tex] = [tex]4.92[/tex] x [tex]2[/tex] = [tex]9.84[/tex] $
Case 2:
A quarter-liter of water costs [tex]1.48[/tex].
The 4 quarter-liters is [tex]1[/tex] liter => The cost of a liter of water ([tex]B[/tex]) is calculated by multiply the cost of [tex]1[/tex] quarter-liter by [tex]4[/tex]:
[tex]B = 1.48[/tex] x [tex]4[/tex] = [tex]5.92[/tex]
=> The cost of two liters: [tex]B_{1} = 5.92[/tex] x [tex]2[/tex] = [tex]11.84[/tex] $
Compare [tex]A_{1}[/tex] and [tex]B_{1}[/tex], the cost of second buying method is more expensive.
=> She should buy the water, in which a half-liter of water costs $[tex]2.46[/tex]
Hope this helps!
:)
