To start off, Labeling the tickets would be the first step. Lets say that Homecoming tickets are X and general admission tickets are Y
so far we know that 150 tickets have been sold, so therefore
X+Y=150
We also know that Homecoming tickets, or X, cost 5 Dollars and General Admission tickets cost 8 Dollars, and so far, they have collected 900 Dollars. Therefore
5X+8Y=900
These 2 Functions will be the 2 functions are your system of equations in standard form, therefore your answer to part A is...
X+Y=150
5X+8Y=900
These 2 functions are also the functions you will be graphing, and the graph iv'e included is the answer to part B of the question.
as to part C, the solution of the system is where the 2 functions intercept, and therefore a quick look at the graph will give you the answer. the axis on my graph are hard to follow, so i will tell you that the answer is (100,50) and you can check this answer by substituting these numbers for the corresponding variables in either equation and both equations should be true. Finally, the answer to part D is no because these 2 functions intersect at one and only one point, being (100,50) so (180,-30) is not a valid answer, and similarly even if you had no idea what the answer was, you could still see that (180,-30) is not a valid answer because -30 represents the amount of general admission tickets, or Y, they had, and its impossible to have -30 tickets. i hope this answer help!
:)
