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: Its D :)
Step-by-step explanation:
Answer:
The correct equation is "y=30x+6147". A further explanation is given below.
Step-by-step explanation:
The given values are:
(x1, y1) = (50, 7647)
(x2, y2) = (100, 9147)
As we know,
The slope is,
⇒ 
On substituting the given values, we get
⇒ 
⇒ 
⇒ 
Now,
⇒ 
On substituting the given values in the above equation, we get
⇒ 
⇒ 
On adding "7647" both sides, we get
⇒ 
⇒ 
You would plug in the y=9 into the first equation and then have the expression 9=9x-9
. After going through the first steps of solving an expression you would get 18=9x. X=2. Then you would plug in the x value into the first expression to get y=9.
Answer:
3.
Step-by-step explanation: