To solve the system of linear equations given by:
- \( 4h + 4s = 10 \)
- \( 7h + 5s = 15 \)
we will solve for \( h \) (the cost of a hot dog) and \( s \) (the cost of a soda) step-by-step.
Step 1: Simplify the first equation
The first equation can be simplified by dividing everything by 4:
\[
h + s = 2.5 \quad \text{(Equation 1)}
\]
Step 2: Solve Equation 1 for \( s \)
We can express \( s \) in terms of \( h \):
\[
s = 2.5 - h \quad \text{(Substitute this into the second equation)}
\]
Step 3: Substitute \( s \) in the second equation
Now substitute \( s \) into the second equation \( 7h + 5s = 15 \):
\[
7h + 5(2.5 - h) = 15
\]
Step 4: Distribute and solve for \( h \)
Distributing the 5:
\[
7h + 12.5 - 5h = 15
\]
Combine like terms:
\[
(7h - 5h) + 12.5 = 15
\]
\[
2h + 12.5 = 15
\]
Step 5: Isolate \( h \)
Subtract 12.5 from both sides:
\[
2h = 15 - 12.5
\]
\[
2h = 2.5
\]
Now divide by 2:
\[
h = \frac{2.5}{2} = 1.25
\]
Step 6: Substitute \( h \) back to find \( s \)
Now use the value of \( h \) to find \( s \):
\[
s = 2.5 - h = 2.5 - 1.25 = 1.25
\]
Conclusion
The solutions are:
\[
h = 1.25 \quad (cost , of , a , hot , dog)
\]
\[
s = 1.25 \quad (cost , of , a , soda)
\]
Final Answer
- \( h = $1.25 \)
- \( s = $1.25 \)