Answer:
B. Recursive
Step-by-step explanation:
I calculated it logically
1. 72 to 50 points
50/72 = 69%
100-69= 31% decrease
2. 14 to 40 books
14 / 40 = 35%
100-35= 65% increase
3. 10 plus 30% increase
10 * 0.3 = 13
Circle formula
(x-h)^2+(y-k)^2=r^2 where (h,k) is the center
and r=radius
to find the radius
we are given one of the points and the center
distnace from them is the radius
distance formula
D=

points (-3,2) and (1,5)
D=

D=

D=

D=

D=5
center is -3,2
r=5
input
(x-(-3))^2+(y-2)^2=5^2
(x+3)^2+(y-2)^2=25 is equation
radius =5
input -7 for x and solve for y
(-7+3)^2+(y-2)^2=25
(-4)^2+(y-2)^2=25
16+(y-2)^2=25
minus 16
(y-2)^2=9
sqqrt
y-2=+/-3
add 2
y=2+/-3
y=5 or -1
the point (-7,5) and (7,-1) lie on this circle
radius=5 units
the points (-7,5) and (-7,1) lie on this circle