The sum of the first four terms of the sequence is 22.
In this question,
The formula of sum of linear sequence is

The sum of the first ten terms of a linear sequence is 145
⇒ 
⇒ 145 = 5 (2a+9d)
⇒ 
⇒ 29 = 2a + 9d ------- (1)
The sum of the next ten term is 445, so the sum of first twenty terms is
⇒ 145 + 445
⇒ 
⇒ 590 = 10 (2a + 19d)
⇒ 
⇒ 59 = 2a + 19d -------- (2)
Now subtract (2) from (1),
⇒ 30 = 10d
⇒ d = 
⇒ d = 3
Substitute d in (1), we get
⇒ 29 = 2a + 9(3)
⇒ 29 = 2a + 27
⇒ 29 - 27 = 2a
⇒ 2 = 2a
⇒ a = 
⇒ a = 1
Thus, sum of first four terms is
⇒ 
⇒ 
⇒ S₄ = 2(2+9)
⇒ S₄ = 2(11)
⇒ S₄ = 22.
Hence we can conclude that the sum of the first four terms of the sequence is 22.
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Answer:
Explanation:
<u>1. Given equation:</u>

<u>2. Given intensity:</u>

<u>3. Decibels</u>

Answer:
Given - Radius of ring is 9 millimeters
To find - Circumference
Solution -
9 millimeters = 0.9 centimeters
Circumference of circle = 2 × pie × r
= 2 × 3.14 × 0.9
= 6.28 × 0.9
= 5.652
Answer:
Step-by-step explanation:
surface area of one can 2πrh+2πr²
=2πr(h+r)
≈2×3.14×3/2(4.25+1.5)
≈9.42(5.75)
≈54.165 in²
number of cans=1000/54.165
=18 cans
material used=18×54.165≈975 in²
material left=1000-975=25 in²
Yes!
- you applied the distributive property
- combined like terms
- and answered the rest right!