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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Answer:
Slope = rise / run
= -12 / 1500 (It's -12 and not 12 because a drop means it's decreasing)
= -0.008
Answer:
70 apples
Step-by-step explanation:
We can use a ratio to solve
7 apples x apples
-------------- = -------------
50 name 500 names
Using cross products
7 * 500 = 50x
Divide by 50
7 * 500/50 = 50x/50
70 =x
The solutions of the equation are -12 and 16
Step-by-step explanation:
Absolute value describes the distance of a number on the number line from 0 without considering which direction from zero the number lies. The absolute value of a number is never negative, if IxI = a, where a > 0, then
∵ 2Ix - 2I - 8 = 20
- At first add 8 to both sides
∴ 2Ix - 2I = 28
- Then divide both sides by 2
∴ Ix - 2I = 14
Now By using the notes above equate x - 2 by 14 and -14
∵ x - 2 = 14
- Add 2 to both sides
∴ x = 16
∵ x - 2 = -14
- Add 2 to both sides
∴ x = -12
The solutions of the equation are -12 and 16
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You can learn more about solving equations in brainly.com/question/2386054
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1 cubic foot has 7.48 gallons of water.
Volume of water tank = 234 cubic feet
So, the number of gallons are = 
Hence, the water tank can hold 1750.32 gallons of water.
