Given:
Total number of hamburgers and cheeseburgers sold = 439
There were 61 fewer cheeseburgers than hamburgers sold.
Let's determine the number of hamburgers sold.
Let C represent the number of cheeseburgers
Let H represent the number of hamburgers sold.
We have the system of equations:
• H + C = 439
,
• C = H - 61
Now, let's solve the equations simultaneously using the substitution method.
Substitute (H - 61) for C in the first equation.
We have:
H + (H - 61) = 439
H + H - 61 = 439
2H - 61 = 439
Add 61 to both sides:
2H - 61 + 61 = 439 + 61
2H = 500
Divide both sides by 2:
[tex]\begin{gathered} \frac{2H}{2}=\frac{500}{2} \\ \\ H=250 \end{gathered}[/tex]
Therefore, they sold 250 hamburgers on Friday.
ANSWER:
250 hamburgers
