Answer:
possible values of 4th term is 80 & - 80
Step-by-step explanation:
The general term of a geometric series is given by

Where a(n) is the nth term, r is the common ratio (a term divided by the term before it) and n is the number of term
- Given, 5th term is 40, we can write:

- Given, 7th term is 10, we can write:

We can solve for a in the first equation as:

<em>Now we can plug this into a of the 2nd equation:</em>
<em> </em>
</em>
<em />
<em>Let's solve for a:</em>
<em> </em>
</em>
<em />
Now, using the general formula of a term, we know that 4th term is:
4th term = ar^3
<u>Plugging in a = 640 and r = 1/2 and -1/2 respectively, we get 2 possible values of 4th term as:</u>

possible values of 4th term is 80 & - 80
 
        
             
        
        
        
83 Cents = 2 Quarters, 1 Nickel, 4 Pennies.
Glad I Could Help, And Good Luck!
~AnonymousGiantsFan~
        
                    
             
        
        
        
Answer:
Step-by-step explanation:
4
 
        
             
        
        
        
17. Yes!! SAS theorem 
18. Yes !! SSS theorem 
19. Yes !! SSS theorem 
20. I don’t think so