A food stall is selling a chicken burger at $3 and a beef burger at $5.
Derick ordered some burgers for his classmates. He ordered 4 more beef burgers than chicken burgers. If he paid a total of $92 for the burgers, how many chicken burgers did he buy?
just add up the costs:
3x + 5(x+4) = 92
x = 9 chicken burgers