Answer:
![26](https://tex.z-dn.net/?f=26)
.
Step-by-step explanation:
The given series is;
![\sum_{n=1}^{4}(n+4)](https://tex.z-dn.net/?f=%5Csum_%7Bn%3D1%7D%5E%7B4%7D%28n%2B4%29)
.
This series is finite and has few number of terms.
We can rewrite the expanded form to get;
![\sum_{n=1}^{4}(n+4)=(1+4)+(2+4)+(3+4)+(4+4)](https://tex.z-dn.net/?f=%5Csum_%7Bn%3D1%7D%5E%7B4%7D%28n%2B4%29%3D%281%2B4%29%2B%282%2B4%29%2B%283%2B4%29%2B%284%2B4%29)
.
![\sum_{n=1}^{4}(n+4)=5+6+7+8](https://tex.z-dn.net/?f=%5Csum_%7Bn%3D1%7D%5E%7B4%7D%28n%2B4%29%3D5%2B6%2B7%2B8)
.
![\sum_{n=1}^{4}(n+4)=26](https://tex.z-dn.net/?f=%5Csum_%7Bn%3D1%7D%5E%7B4%7D%28n%2B4%29%3D26)
.
Answer:
A: 2.9 x $4.25 = 12.325 or 12.33
B: 1.6 x $5.15 = $8.24
$12.33 + $8.24 = $20.57
Step-by-step explanation:
8.302, 8.32, 8.3212, and then 8.4
Answer:
The average speed of the 747 was of 580 miles per hour.
Step-by-step explanation:
We use the following relation to solve this question:
![v = \frac{d}{t}](https://tex.z-dn.net/?f=v%20%3D%20%5Cfrac%7Bd%7D%7Bt%7D)
In which v is the velocity, d is the distance and t is the time.
A small airplane flies 1015 miles with an average speed of 290 miles per hour.
We have to find the time:
![v = \frac{d}{t}](https://tex.z-dn.net/?f=v%20%3D%20%5Cfrac%7Bd%7D%7Bt%7D)
![290 = \frac{1015}{t}](https://tex.z-dn.net/?f=290%20%3D%20%5Cfrac%7B1015%7D%7Bt%7D)
![290t = 1015](https://tex.z-dn.net/?f=290t%20%3D%201015)
![t = \frac{1015}{290}](https://tex.z-dn.net/?f=t%20%3D%20%5Cfrac%7B1015%7D%7B290%7D)
![t = 3.5](https://tex.z-dn.net/?f=t%20%3D%203.5)
1.75 hours after the plane leaves, a Boeing 747 leaves from the same point. Both planes arrive at the same time;
The time of the Boeing 747 is:
![t = 3.5 - 1.75 = 1.75](https://tex.z-dn.net/?f=t%20%3D%203.5%20-%201.75%20%3D%201.75)
Distance of
, the velocity is:
![v = \frac{d}{t} = \frac{1015}{1.75} = 580](https://tex.z-dn.net/?f=v%20%3D%20%5Cfrac%7Bd%7D%7Bt%7D%20%3D%20%5Cfrac%7B1015%7D%7B1.75%7D%20%3D%20580)
The average speed of the 747 was of 580 miles per hour.