Answer:
Elimination 
Step-by-step explanation:
You would not do substitution since it would not work so you do elimination since the 4y and -4y eliminate then you just solve for it.
 
        
             
        
        
        
Assuming the series is

The series will converge if

We have

So the series will certainly converge if 

, but we also need to check the endpoints of the interval.
If 

, then the series is a scaled harmonic series, which we know diverges.
On the other hand, if 

, by the alternating series test we can show that the series converges, since

and is strictly decreasing.
So, the interval of convergence for the series is 

.
 
        
        
        
Well, remember
(ab)(cd)=abcd=(ac)(bd)
so 
(8t^5)(8t^5)=(8)(t^5)(8)(t^5)=(8*8)(t^5*t^5)=64t^10
        
             
        
        
        
Answer:
c= 12t
c is the amount of energy you burn, so it'll be the "solution" to the equation. Multiply 12 times the amount of time you spend exercising to find how much energy you'll burn.