18. S=r^2-t^2
S+t^2=r^2
r=sqrt(S+t^2)
20. Tan 18=x/12
x=12×Tan 18
x=3.899036355
x=3.90
I hope this helps.
Step-by-step explanation:
The standard equation of a circle is 
Center = (h, k)
#1
Center = (0,2)
h = 0
k = 2
r = 5


#2
Center = (-4,-5)
h = -4
k = -5
r = 



#3
Center =(-1,3)
h = -1
k = 3
r = 8



#4
Center: (9,0)
h = 9
k = 0
r = 


Answer: the Nswer for this is 30 people
Step-by-step explanation:
Rearrange:
Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :
4*x-1+2*x-9-(152)=0
Step by step solution :
Step 1 :
Pulling out like terms :
1.1 Pull out like factors :
6x - 162 = 6 • (x - 27)
step 2
Solving a Single Variable Equation :
2.2 Solve : x-27 = 0
Add 27 to both sides of the equation :
x = 27
One solution was found :
x = 27
brainliest plzzz worked really hard on this thx god bless