Answer:

Step-by-step explanation:
The terms of this sum make the arithmetic sequence.
The fomula of a sum of <em>n</em> terms of an arithmetic sequence:
![S_n=\dfrac{[2a_1+(n-1)d]\cdot n}{2}](https://tex.z-dn.net/?f=S_n%3D%5Cdfrac%7B%5B2a_1%2B%28n-1%29d%5D%5Ccdot%20n%7D%7B2%7D)
We have

Substitute:
![S_{50}=\dfrac{[2\cdot2+(50-1)\cdot15]\cdot50}{2}=(4+49\cdot15)\cdot25=(4+735)\cdot25\\\\=739\cdot25=18,475](https://tex.z-dn.net/?f=S_%7B50%7D%3D%5Cdfrac%7B%5B2%5Ccdot2%2B%2850-1%29%5Ccdot15%5D%5Ccdot50%7D%7B2%7D%3D%284%2B49%5Ccdot15%29%5Ccdot25%3D%284%2B735%29%5Ccdot25%5C%5C%5C%5C%3D739%5Ccdot25%3D18%2C475)
I’m not sure about number 1 but the answer for number 2 is
-4 1/2, -4.2, -4, ,0, 4
Answer:
n < 27
Step-by-step explanation:
let the number be n

Given:
Current population = x
The population of a city is expected to decrease by 6% next year.
To find:
The expression that represents the expected population next year.
Solution:
We have,
Current population = x
Decrease rate = 6%.
Expected population next year = Current population - 6% of Current population
=
=
=
Therefore, the expression for the expected population next year is 0.94x.