Answer:
.
Step-by-step explanation:
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:
mx -y = 4m -7
Step-by-step explanation:
Standard form is ...
ax +by = c
where a, b, c are mutually prime integers and a > 0.
If we assume m > 0, then we need to collect the variable terms on the right side of the equation, so the coefficient of x will be positive.
y -7 = mx -4m . . . . eliminate parentheses
-7 = mx -y -4m . . . . subtract y
4m -7 = mx -y . . . . . add 4m
mx -y = 4m -7 . . . . . . standard form
The absolute value of 6.7 is 6.7