Need help asap plz <3✨ PLEASE ANSWER THE QUESTION THX :)
1 answer:
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Answer:
Step-by-step explanation:
The equation for an arithmetic sequence is
where n is the position of the number in the sequence, a1 is the first number in the sequence, and d is the difference between the numbers in the sequence.
Our first number is 2, so a1 = 2; to get from 2 to 5 we add 3, to get from 5 to 8 we add 3. That means that d = 3. Filling in the standard form of the equation:
which simplifies to
and a bit more to
(which should tell you that arithmetic sequences are lines!)
Finding the 13th number simply requires that we replace n with 13 and solve:
so
Sum of geometric sequence
for the sum where the initial value is a₁ and the common ratio is r and the term is n
common ratio is -3
-5 times -3 is 15, -15 times -3=-45 etc
first term is -5
and we want the 8th term
the sum is 8200
for the sum where the initial value is a₁ and the common ratio is r and the term is n
common ratio is -3
-5 times -3 is 15, -15 times -3=-45 etc
first term is -5
and we want the 8th term
the sum is 8200