Answer:

Step-by-step explanation:
In order to write the series using the summation notation, first we need to find the nth term of the sequence formed. The sequence generated by the series is an arithmetic sequence as shown;
4, 8, 12, 16, 20...80
The nth term of an arithmetic sequence is expressed as Tn = a +(n-1)d
a is the first term = 4
d is the common difference = 21-8 = 8-4 = 4
n is the number of terms
On substituting, Tn = 4+(n-1)4
Tn = 4+4n-4
Tn = 4n
The nth term of the series is 4n.
Since the last term is 80, L = 4n
80 = 4n
n = 80/4
n = 20
This shows that the total number of terms in the sequence is 20
According to the series given 4 + 8 + 12 + 16 + 20+ . . . + 80
, we are to take the sum of the first 20terms of the sequence. Using summation notation;
4 + 8 + 12 + 16 + 20+ . . . + 80 = 
Answer:
The measure of an interior angle of a regular 15-gon is 120°.
Step-by-step explanation:
We need to determine the measure of the size of an interior angle of a regular 15-gon having 15 sides.
Thus,
The number of sides n = 15
Hence,
Using the formula to determine the measure of an interior angle of a regular 15-gon is given by
(n - 2) × 180° = n × interior angle
substitute n = 15
(15 - 2) × 180 = 15 × interior angle
13 × 180 = 15 × interior angle
Interior angle = (10 × 180) / 15
= 1800 / 15
= 120°
Therefore, the measure of an interior angle of a regular 15-gon is 120°.
None of the two answer choices are correct, answer is none of the above
simplify by multiplying by 2 we get 10g+6h+8. neither of the two choices match
I think the answer is 4.20 hours and minutes planning the last road trip .
111,000 because you do 30000+32000+49000.