Answer: The School band sold a total of; 180 hamburgers and 120 hotdogs.
Step-by-step explanation: For a start we shall represent hotdogs by the letter d and hamburgers by the letter b. If they sold a total of 300 hotdogs and hamburgers, then we can express this as, d + b = 300.
Also if one hotdog was sold for $2 and one hamburger was sold for $3, and altogether realized $780,this can also be expressed as, 2d + 3b = 780.
We now have a pair of simultaneous equations as follows;
d + b = 300 ———(1)
2d + 3b = 780 ———(2)
From equation (1), make d the subject of the equation. Therefore d = 300 - b
Substitute for d into equation (2)
2(300 - b) + 3b = 780
600 - 2b + 3b = 780
Collect like terms
3b - 2b = 780 - 600
b = 180
We can now substitute for the value of b into equation (1)
d + b = 300
d + 180 = 300
Subtract 180 from both sides of the equation
d = 120
Therefore, the school band sold 180 hamburgers and 120 hotdogs