Respuesta :
Given
First, let's summarize the costs of each ingredient
Distilled Water: $2/gallon
Diet cola: $4/gallon
Diluted alchohol: $1/gallon
Total = 8 gallons
Cost = $18
Batch of goo uses the same amount of Water an Cola
Procedure
Let's formulate a system of equations to define the problem we have.
w = gallons of water
c = gallons of cola
a = gallons of alcohol
The first equation we can create is using the total amount of gallons created.
[tex]w+c+a=8[/tex]Now we can create an equation associated with costs and total cost
[tex]2w+4c+a=18[/tex]As you can see in our system we have 3 unknowns so we need a third equation.
For this we use the information that we need the same amount of Cola and Water.
[tex]w=c[/tex]8a) Let's write this as a system of equations
[tex]\begin{gathered} w+c+a=8 \\ 2w+4c+a=18 \\ w=c \end{gathered}[/tex]8b) Now let's proceed to solve the system of equations
[tex]\begin{gathered} w=c,\text{ therefore } \\ w+w+a=8 \\ 2w+4w+a=18 \\ \\ 2w+a=8\text{ (1)} \\ 6w+a=18\text{ (2)} \\ \text{ using 1: } \\ a=8-2w,\text{ therefore} \\ 6w+8-2w=18 \\ 4w=18-8 \\ 4w=10 \\ w=10/4 \\ w=2.5 \end{gathered}[/tex]As we know w = c, therefore c = 2.5. Now, for a
[tex]\begin{gathered} a=8-2\cdot2.5 \\ a=3.0\text{ } \end{gathered}[/tex]Water = 2.5 gallons
Cola = 2.5 gallons
Alcohol = 3.0 galons