a concession stand sells hamburgers (h) for $2 and hotdogs (d) for $1

on a friday night they sold a total of 300 hamburgers and hotdogs and made $420 how many did they sell which system of equations matched the situation

Let's use the following system of equations:

h + d = 300 (equation 1 - total number of hamburgers and hotdogs sold is 300)
2h + d = 420 (equation 2 - total revenue made is $420)

This system of equations matches the situation.