Answer:
Step-by-step explanation:
 
        
             
        
        
        
Circumference of a circle is 2 x pi x r 
        
                    
             
        
        
        
Ok, to solve this first you have to set up your proportion:
9/150=x/230
/ is a fraction
x= the number of vials it will take to treat 230 patients
in order to solve this, you have to cross multiply:
9 x 230= 2070
150 · x= 150x
so you get 150x=2070
then divide 2070 by 150
2070/150= 13.8
so it would take 13.8 vials of medicine to treat 230 patients
        
                    
             
        
        
        
Answer:
Step-by-step explanation:
x^2 = 64
√x² = √64
x = 8, -8
answer is B
 
        
             
        
        
        
Answer:
Please check the explanation.
Step-by-step explanation:
Finding Domain:
We know that the domain of a function is the set of input or argument values for which the function is real and defined.
From the given graph, it is clear that the starting x-value of the line is x=-2, the closed circle at the starting value of x= -2 means the x-value x=-2 is included. 
And the line ends at the x-value x=1 with a closed circle, meaning the ending value of x=1 is also included.
Thus, the domain is:
D: {-2, -1, 0, 1}       or    D: −2 ≤ x ≤ 1
Finding Range:
We also know that the range of a function is the set of values of the dependent variable for which a function is defined
From the given graph, it is clear that the starting y-value of the line is y=0, the closed circle at the starting value of y = 0 means the y-value y=0 is included. 
And the line ends at the y-value y=2 with a closed circle, meaning the ending value of y=2 is also included.
Thus, the range is:
R: {0, 1, 2}   or    R: 0 ≤ y ≤ 2