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
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we have the price of TV is $3960.if we round off to the nearest tens we get same 3960 because we have 0 at the end which means lesser than 5 so 60 will be the nearest ten.
discount =
so $990 will be the discount.
and the cost of TV after discount is 
If you would like to solve the inequality x - 5/x < 4, you can do this using the following steps:
<span>x - 5/x < 4
</span>x^2 - 5 < 4x
x^2 - 4x - 5 < 0
(x - 5) * (x + 1) < 0
x < 0
1. x = 5
2. x = -1
The correct result would be x = -1.
Answer:
there would be 100
Step-by-step explanation:
140:100=70:50=7:5
Answer:
19.2
Step-by-step explanation:
12 squared + 15 squared= C squared
144 + 225 = C squared
369 = C squared
Do square root of 369, which is
19.2