Answer:
C
Step-by-step explanation:
If you plug in 4 to the equation it looks like this:
48-5= 20+23. Subtract 5 and add 23, to get 43=43. That statement is true so it's 4.
Answer:
Radius of the convergence is R = 
and,
The Interval of convergence is 
Step-by-step explanation:
Given function : Σ(21x)^k
Now,
Using the ratio test, we have
R = 
or
R = 
or
R = 
now,
for convergence R|x| < 1
Therefore,
< 1
or

and,
Radius of the convergence is R = 
and,
The Interval of convergence is 
Answer:
54
Step-by-step explanation:
75% of 72 is 54