Answer:
5 +4(n -1)
Step-by-step explanation:
The wording "the same number of sticks is added each time" tells you this is an arithmetic sequence. To find the rule, you need to know ...
- the number of sticks in the first pattern: 5
- the number of sticks added each time: 4
The form of the rule for the n-th term of an arithmetic sequence is ...
an = a1 +d(n -1) . . . . . . a1 = first term; d = common difference
For a1 = 5 and d = 4, your rule for the n-th pattern is ...
sticks in n-th pattern = 5 +4(n -1)
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This can be simplified to 1 +4n.
