Answer:
C =131.88 meters
Step-by-step explanation:
The circumference of a circle is given by
C = 2*pi*r
where r is the radius
C = 2 * pi * 21
C = 42 pi
If we approximate pi by 3.14
C = 42(3.14)
C =131.88 meters
First, rearrange the equation so that it is solving for y:
3x - y = 1
+y +y
3x = y + 1
-1 -1
3x - 1 = y
Now substitute the domain values you have listed into the 'x' of the equation to get the values for y.
For example:
3(-3) - 1 = y
-9 - 1 = y
y = -10
For both of the contests, the variable is the number of competitors which we can set as x.
Consequently, the equation should be 5.50x+34.60=4.25x+64.60
5.50x=4.25x+30
1.25x=30
x=24
The fee of the contests is the same when there are 24 competitors
The inequality that represents the graph in the box is

Given :
The graph of the linear inequality
Lets pick two points from the graph to frame the linear equation
Slope intercept form of the equation is

Where m is the slope and b is the y intercept
y intercept is (0,6) from the graph
so b=6
Now we find out slope m using formula
Pick two points (0,6) and (2,0)

m=-3
So the equation is 
Now we check the inequality sign by testing any point on shaded area
lets pick (4,0)
lets plug in 4 for x and 0 for y

The inequality for the given graph is

we cannot use >= sign because we have dotted lines
Learn more : brainly.com/question/17203372
D=number of dogs
c=cats
d equals 4 less than 2 times c
d=-4+2c
20 dogs
d=20
subsitute
20=-4+2c
add 4
24=2c
divide 2
12=c
12 cats