Answer:
3(4+x)
which can be simplified to 12+3x
 
        
             
        
        
        
Looks like your function is

Rewrite it as

Recall that for  , we have
, we have

If we replace  with
 with  , we get
, we get

By the ratio test, the series converges if

Solving for  gives the interval of convergence,
 gives the interval of convergence,

We can confirm that the interval is open by checking for convergence at the endpoints; we'd find that the resulting series diverge.
 
        
             
        
        
        
Answer:
One of the solution is 2
Step-by-step explanation:
 
        
             
        
        
        
Mistake in Line 2 : Was in the determining the values for a ,b,c
Mistake in Line 4 : Not taking the square roots of both sides.
Step-by-step explanation:

First Mistake : Line 2

Second Mistake : Line 4

Correct Solution :

