Can you show the multiple choice one
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
He still has 75% of his income left because 1500/375=4 so he spent 1/4 of his check and has 3/4 left.
Find the change
the change is 63-21=42
42 degrees in 12 hours
we want to find xdegrees/1hour
42/12=3.5 degrees per hour
135° I think 1080( what the angles add up to) 1080÷8=135°