Answer:
the common difference is 6.
Step-by-step explanation:
Given;
first term of an AP, a = -7
let the common difference = d
The third term is written as;
T₃ = a + 2d
The eight term is written as;
T₈ = a + 7d
The ratio of the eight term to third term = 7:1
Therefore, the common difference is 6.
Answer:
i’m thinking it might be 10?
Step-by-step explanation:
Answer:
a=4220-2t
This would be if we are finding the altitude of the submarine from the surface of the water(how many meters away from the surface it is). I don't know what it would be if you want to know from the bottom of the ocean.
Given:
To find:
Solution:
Putting the equation (i) value into equation (ii):
Putting the value of (d) into equation (i):
Calculating the 
Formula:
![\bold{S_n = \frac{n}{2}[2a + (n - 1)d ] }\\](https://tex.z-dn.net/?f=%5Cbold%7BS_n%20%3D%20%5Cfrac%7Bn%7D%7B2%7D%5B2a%20%2B%20%28n%20-%201%29d%20%5D%20%7D%5C%5C)
Calculating the 
![\to \bold{S_{10} = \frac{10}{2}[2\frac{10}{3} + (10- 1)\frac{5}{3} ] }\\\\\to \bold{S_{10} = 5[\frac{20}{3} + (9)\frac{5}{3} ] }\\\\\to \bold{S_{10} = 5[\frac{20}{3} + 9 \times \frac{5}{3} ] }\\\\\to \bold{S_{10} = 5[\frac{20}{3} + 3\times 5 ] }\\\\\to \bold{S_{10} = 5[\frac{20}{3} + 15 ] }\\\\\to \bold{S_{10} = 5[\frac{20+ 45}{3} ] }\\\\\to \bold{S_{10} = 5[\frac{65}{3} ] }\\\\\to \bold{S_{10} = 5 \times \frac{65}{3} }\\\\\to \bold{S_{10} = \frac{325}{3} }\\\\\to \bold{S_{10} =108.33 }](https://tex.z-dn.net/?f=%5Cto%20%5Cbold%7BS_%7B10%7D%20%3D%20%5Cfrac%7B10%7D%7B2%7D%5B2%5Cfrac%7B10%7D%7B3%7D%20%2B%20%2810-%201%29%5Cfrac%7B5%7D%7B3%7D%20%5D%20%7D%5C%5C%5C%5C%5Cto%20%5Cbold%7BS_%7B10%7D%20%3D%205%5B%5Cfrac%7B20%7D%7B3%7D%20%2B%20%289%29%5Cfrac%7B5%7D%7B3%7D%20%5D%20%7D%5C%5C%5C%5C%5Cto%20%5Cbold%7BS_%7B10%7D%20%3D%205%5B%5Cfrac%7B20%7D%7B3%7D%20%2B%209%20%5Ctimes%20%5Cfrac%7B5%7D%7B3%7D%20%5D%20%7D%5C%5C%5C%5C%5Cto%20%5Cbold%7BS_%7B10%7D%20%3D%205%5B%5Cfrac%7B20%7D%7B3%7D%20%2B%203%5Ctimes%205%20%5D%20%7D%5C%5C%5C%5C%5Cto%20%5Cbold%7BS_%7B10%7D%20%3D%205%5B%5Cfrac%7B20%7D%7B3%7D%20%2B%2015%20%5D%20%7D%5C%5C%5C%5C%5Cto%20%5Cbold%7BS_%7B10%7D%20%3D%205%5B%5Cfrac%7B20%2B%2045%7D%7B3%7D%20%5D%20%7D%5C%5C%5C%5C%5Cto%20%5Cbold%7BS_%7B10%7D%20%3D%205%5B%5Cfrac%7B65%7D%7B3%7D%20%5D%20%7D%5C%5C%5C%5C%5Cto%20%5Cbold%7BS_%7B10%7D%20%3D%205%20%5Ctimes%20%5Cfrac%7B65%7D%7B3%7D%20%20%7D%5C%5C%5C%5C%5Cto%20%5Cbold%7BS_%7B10%7D%20%3D%20%20%5Cfrac%7B325%7D%7B3%7D%20%20%7D%5C%5C%5C%5C%5Cto%20%5Cbold%7BS_%7B10%7D%20%3D108.33%20%7D)
Therefore, the final answer is " 
"
Learn more:
brainly.com/question/11853909
C 63 i guesses dude but can be 50 right or wrong
