Use the given values in the compound interest formula to solve for time, n.
A is the final amount of money, $2800
P is the initial or starting amount $1900
i is the interest rate as a decimal 0.025
n is time in years since it annual.
2800 = 1900(1 + 0.025)^n
2800 = 1900(1.025)^n
2800/1900 = (1.025)^n
28/19 = (1.025)^n
take the natural log of both sides to solve for exponent.
ln(28/19) = ln(1.025^n)
power rule of logarithmic moves exponent
ln(28/19) = n*ln(1.025)
ln(28/19) / ln(1.025) = n
put into a calculator
15.7 years = n
30+x=42 I think because it's has to equal 42 and he already has 30
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:
240
Step-by-step explanation:
well do *
so 8x6x5 = 240 there's your answer
7 1\5=7x5+1=36\5
36\5 x 100=720%