Answer:
[-20.25;+∞).
Step-by-step explanation:
1) according to the properties of the given parabola the minimum is:

2) y₀=-20.25 means, the value -20.25 is minimum of the range, the maximum →+∞;
3) finally, the range y≥-20.25.
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
This breaks into two inequalities:
2x - 3 > 6
and
-2x + 3 > 6
------------------------
2x - 3 > 6
Add 3 to both sides:
2x > 9
Divide 2 to both sides:
x > 4.5
-----------------------
-2x + 3 > 6
Subtract 3 to both sides:
-2x > 3
Divide -2 to both sides:
x < -1.5
Times it bye 4 thin subtract bye 6
That’s a hard one for sure but I would say six