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
Answer:
(A)


(B)

(C)

(D)
The high school's enrollment in 2017 is 2500
Step-by-step explanation:
Let's assume time starts since 2009
so, In 2009 , t=0
P=900
In 2012,
t=2012-2009=3
P=1500
(A)
So, we have points as


(B)
we can use slope formula

we can plug values


we know that
slope is rate of change of P with respect to time
so, slope means increase in population is 200 per year
(C)
we can use point slope form of line





(D)
In 2017 ,
t=2017-2009=8
we can plug t=8
and we get


The high school's enrollment in 2017 is 2500
Answer:
Adults = x
Students = y = x + 40. 40 more student than adult
Adult = $8, Student = $6
Total for Adults = 8*x = 8x
Total for students = 6*y = 6y
Total = $1920
8x + 6y = 1920
Hence system of equations are:
y = x + 40
8x + 6y = 1920