Step-by-step explanation:
To find the formula for the nth term ,
First , find the common difference or common ratio.
Common difference =

Common ratio =

The common difference applies to the other given numbers for example :

this proves that it is an arithmetic sequence and the given formula for the nth term of an arithmetic sequence is
T_n =a(n-1)d
Where n = no of terms
a= first term
d= common difference
Answer:
w = 10
Step-by-step explanation:
9(w - 9) -2 = -7 + 7(w -8)
Expand:
9w - 81 - 2 = -7 + 7w - 56
Rearrange:
9w - 7w = -7 - 56 + 81 + 2
2w = 20
w = 10
The relation between pressure and volume is given as
v = 18000/p
where
v = volume, in³
p = pressure, lb/in²
When the pressure is p = 900 lb/in², then the volume is
v = 18000/900 = 20 in³
Answer: 20 in³