Answer:
Step-by-step explanation:
The formula for determining the sum of the first n terms of an arithmetic sequence is expressed as
Sn = n/2[2a + (n - 1)d]
Where
n represents the number of terms in the arithmetic sequence.
d represents the common difference of the terms in the arithmetic sequence.
a represents the first term of the arithmetic sequence.
If a = 5, the expression for the sum of the first 12 terms is
S12 = 12/2[2 × 5 + (12 - 1)d]
S12 = 6[10 + 11d]
S12 = 60 + 66d
Also, the expression for the sum of the first 3 terms is
S3 = 3/2[2 × 5 + (3 - 1)d]
S3 = 1.5[10 + 2d]
S3 = 15 + 3d
The sum of the first 12 terms is equal to ten times the sum of the first 3 terms. Therefore,
60 + 66d = 10(15 + 3d)
60 + 66d = 150 + 30d
66d + 30d = 150 - 60
36d = 90
d = 90/36
d = 2.5
For S20,
S20 = 20/2[2 × 5 + (20 - 1)2.5]
S20 = 10[10 + 47.5)
S20 = 10 × 57.5 = 575
Answer:
The actual water in the tank is 29.76 gallons.
Step-by-step explanation:
It is given that the farmer estimated amount of water is 25 gallons.
It is also given that he underestimate the water in tank by 16%.
Let the actual water in tank be x.
Therefore the actual water in the tank is 29.76 gallons.
1000 = x^3
1000 cube root = x
10 = x
10*10 = 100
100*10 = 1000
Hope this helped, and please make me brainlest! :)
You need to find the number of books per days, so start out with 6/8. The 6 represents the bookcases and the 8 is the # of days. 6/8=3/4
Answer: 3/4 bookcases per day. (I hope that's right!)
If x = 1.5, than the length of the straw before it is folded is 21 inches. You can find this in the following steps :
12(1.5)^2 -6 = length
12(2.25) -6 =
27 -6 =
21
Your answer is: 21 inches
Have an amazing day mate!
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