Students are selling hot dogs and sodas. Each hot dog costs [tex]\$ 1.50[/tex] and each soda costs [tex]\$ 0.50[/tex]. They made a total of [tex]\$ 78.50[/tex]. They sold a total of 87 hot dogs and sodas combined. How many hot dogs and how many sodas were sold? Write the system of equations.

[tex]\[
\begin{cases}
1.5x + 0.5y = 78.5 \\
x + y = 87
\end{cases}
\][/tex]



Answer :

To solve the problem of determining the number of hot dogs and sodas sold, let's set up and solve a system of linear equations based on the given information.

Let's denote:
- [tex]\( x \)[/tex] as the number of hot dogs sold.
- [tex]\( y \)[/tex] as the number of sodas sold.

Given:
- Each hot dog costs [tex]$\$[/tex]1.5[tex]$. - Each soda costs $[/tex]\[tex]$0.5$[/tex].
- The total income from sales is [tex]$\$[/tex]78.5$.
- The total number of items (hot dogs and sodas) sold is 87.

We can formulate the following system of equations:
1. The equation representing the total sales in dollars:
[tex]\[ 1.5x + 0.5y = 78.5 \][/tex]

2. The equation representing the total number of items sold:
[tex]\[ x + y = 87 \][/tex]

So our system of equations is:
[tex]\[ \begin{cases} 1.5x + 0.5y = 78.5 \\ x + y = 87 \end{cases} \][/tex]

### Step-by-Step Solution

1. Multiply the second equation by 0.5 to align the coefficients of [tex]\( y \)[/tex] for elimination:
[tex]\[ 0.5(x + y) = 0.5 \times 87 \][/tex]
[tex]\[ 0.5x + 0.5y = 43.5 \][/tex]

2. Subtract this equation from the first equation to eliminate [tex]\( y \)[/tex]:
[tex]\[ (1.5x + 0.5y) - (0.5x + 0.5y) = 78.5 - 43.5 \][/tex]
[tex]\[ (1.5x - 0.5x) = 35 \][/tex]
[tex]\[ 1x = 35 \][/tex]
[tex]\[ x = 35 \][/tex]

3. Substitute [tex]\( x = 35 \)[/tex] back into the second equation to find [tex]\( y \)[/tex]:
[tex]\[ 35 + y = 87 \][/tex]
[tex]\[ y = 87 - 35 \][/tex]
[tex]\[ y = 52 \][/tex]

Thus, the number of hot dogs sold is 35, and the number of sodas sold is 52.

[tex]\[ \boxed{35 \text{ hot dogs}, 52 \text{ sodas}} \][/tex]