The given sequence is
a₁, a₂, ...,

Because the given sequence is an arithmetic progression (AP), the equation satisfied is

where
d = the common difference.
The common difference may be determined as
d = a₂ - a₁
The common difference is the difference between successive terms, therefore
d = a₃ - a₂ = a₄ - a₃, and so on..
The sum of the first n terms is

Example:
For the arithmetic sequence
1,3,5, ...,
the common difference is d= 3 - 1 = 2.
The n-th term is

For example, the 10-term is
a₁₀ = 1 + (10-1)*2 = 19
Th sum of th first 10 terms is
S₁₀ = (10/2)*(1 + 19) = 100
Answer:
a) 0.125
b) 0.015635
c) 0.00000095367431640625
Step-by-step explanation:
a) 
b) 
c) 
15y - 9 <36.
Add 9 to each side.
15y- 9 (+9) < 36 + 9.
15y < 45.
y < 3.
Hope it helps! :)
Emma wanted to buy some apples from the store. They each cost $0.5. If Emma paid $12.5 in total, how many apples did Emma buy?
I did this before and the answer is b