A circle with center 
and radius 
has equation
If we substitute 
in this equation, we have
This equation has two solutions (i.e. the line intersects the circle in two points) if and only if the determinant is greater than zero:
The expression simplifies to
The solutions to the associated equation are
So, the parabola is negative between the two solutions:
Answer: He read 40% of the total time.
Step-by-step explanation:
As per given,
Total time he spent = 2 +1+2 = 5 hours
Number of hours he spent on reading = 2 hours
The percent of the total time he read = 
i.e. The percent of the total time he read = 40%
Hence, he read 40% of the total time.
Answer:
Step-by-step explanation:
x + y = 40
x>y
(11/2)y - (13/4)*x = - 25
x = 40 - y
(11/2)y - (13/4)(40-y) = - 25 multiply by 4
22y - 13( 40 - y) = - 100
22y - 520 + 13y = -400 Add 520
35y = 120
y = 120 / 35
y = 3 3/7
x = 40 - y
x = 36 4/7
It would have to be letter B because the exponents add up to the lines in the graph so in conculsion it is letter B.
