The answer is 18 because you multiply 4 times 3 and then you add the 6 which equals 18
Answer:
9 and 10 i dont know why they have us doing this confusing stuff
Step-by-step explanation:
Answer: it will take 2 months.
Step-by-step explanation:
Let x represent the number of months it will take for the total cost for both companies to be equal.
Company A: $80 for a new phone and the monthly fee of $45 a month. This means that the total amount that Company A charges for x months would be
80 + 45x
Company B: she can keep her all sound and pay $85 a month. This means that the total amount that Company B charges for x months would be
85x
For the total cost for both companies to be equal, the number of months would be
80 + 45x = 85x
85x - 45x = 80
40x = 80
x = 80/40 = 2
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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