Answer:
show in attachment
Step-by-step explanation:
 
        
             
        
        
        
3, 15, 75, 375, and here's why:
Basically, it's asking you to take 3, and multiply it by five each time to get a pattern.
1: 3
2: 3*5 = 15
3: 15*5 = 75
4: 75*5 = 375
Add these together: 
3 + 15 + 75 + 375 = 468
Your answer is "A)", 468.
        
             
        
        
        
X^-n duals: 1/x^n. You cannot have negative exponents so do its inverse to get rid of the negative exponent
        
             
        
        
        
It's important that you share the complete question.  What is your goal here?  Double check to ensure that you have copied the entire problem correctly.
The general equation of a circle is x^2 + y^2 = r^2.  Here we know that the circle passes thru two points:  (-3,2) and (1,5).  Given that a third point on the circle is (-7, ? ), find the y-coordinate of this third point.
Subst. the known values (of the first point) into this equation:  (-3)^2 + (2)^2 = r^2.  Then 9 + 4 = 13 = r^2.
Let's check this.  Assuming that the equation of this specific circle is 
x^2 + y^2 = r^2 = 13, the point (1,5) must satisfy it.
(1)^2 + (5)^2 = 13 is not true, unfortunately.
(1)^2 + (5)^2 = 1 + 25 = 26 (very different from 13).
Check the original problem.  If it's different from that which you have shared, share the correct version and come back here for further help.
        
             
        
        
        
     56
   28  2
 14 2 | 2
7 2 | 2 | 2
or 
    56
  14 4
7 2 | 2 2