Answer:
Arithmetic sequence states that it is a sequence of numbers such that the difference of any two successive members of the sequence is a constant(d)
The rule for the sequence is:

where a is the first term , d is the common difference and n is the number of terms.
Given the pattern: 101, 94, 87, 80.
First term (a) = 101
This pattern is an arithmetic sequence with common difference(d) = -7
Since,
94 -101 = -7
87 -94 = -7
80- 87 = -7
The rule for this pattern is;

or

Therefore, the rule for this pattern is,
where n is the number of term.