Answer:
brainly.com/question/17024807
Step-by-step explanation:
This question was already asked and I don't want to take that person's credit, but I recommend you going to that link because it has steps, plus the answer!
The sum of the first 20 terms of an arithmetic sequence with the 18th term of 8.1 and a common difference of 0.25 is 124.5
Given,
18th term of an arithmetic sequence = 8.1
Common difference = d = 0.25.
<h3>What is an arithmetic sequence?</h3>
The sequence in which the difference between the consecutive term is constant.
The nth term is denoted by:
a_n = a + ( n - 1 ) d
The sum of an arithmetic sequence:
S_n = n/2 [ 2a + ( n - 1 ) d ]
Find the 18th term of the sequence.
18th term = 8.1
d = 0.25
8.1 = a + ( 18 - 1 ) 0.25
8.1 = a + 17 x 0.25
8.1 = a + 4.25
a = 8.1 - 4.25
a = 3.85
Find the sum of 20 terms.
S_20 = 20 / 2 [ 2 x 3.85 + ( 20 - 1 ) 0.25 ]
= 10 [ 7.7 + 19 x 0.25 ]
= 10 [ 7.7 + 4.75 ]
= 10 x 12.45
= 124.5
Thus the sum of the first 20 terms of an arithmetic sequence with the 18th term of 8.1 and a common difference of 0.25 is 124.5
Learn more about arithmetic sequence here:
brainly.com/question/25749583
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Answer:
In the document, Westing names the sixteen heirs present as his “nieces and nephews” and says that tomorrow his ashes “will be scattered to the four winds.” He then asserts that his life has been taken by one of his heirs, and he promises that the heir who finds something will receive the inheritance
Step-by-step explanation:
42 divided by 7 =6 then u times 5 and 6 together . Then times 2 by 6 together so the answer is 30:12
Answer: $53
Step-by-step explanation:
17+ .09m = 9 + .11m
8 = .02m
m = 8/.02= 400 minutes for the two plans to cost the same
9+.11(400) = 9+ 44 = $53 when they cost the same
17+.09(400) = 17 +36 = $53
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