3.14 - 3a Radians
Because
180o = 3.14 radian
Each X and Y in the equations don't have a number in front of them so they are all considered 1.
D = 1*(-1) - 1*(-1) = -1 -1 = -2
The answer is -2
Please put more details in the question
Let X= the number of tickets sold at $35 each
Let 350 -X = the number of tickets sold at $25 each
The number of tickets sold for each type will be computed as follows:
X(35)+(350-X)25=10250
35X+8750-25X=10250
10X=10250-8750
X=1500/10
X=150 the number of tickets sold at $35 each
350-150 the number of tickets sold at $25 each
To recheck:
150(35)+200(25)
5250+5000
10250