Answers:
x = -8/5 or x = 8/5
Sum of the first ten terms where all terms are positive = 4092
========================================================
Explanation:
r = common ratio
- first term = 4
- second term = (first term)*(common ratio) = 4r
- third term = (second term)*(common ratio) = (4r)*r = 4r^2
The first three terms are: 4, 4r, 4r^2
We're given that the sequence is: 4, 5x, 16
Therefore, we have these two equations
Solve the second equation for r and you should find that r = -2 or r = 2 are the only possible solutions. If r = -2, then 5x = 4r solves to x = -8/5. If r = 2, then 5x = 4r solves to x = 8/5.
-----------------
To find the sum of the first n terms, we use this geometric series formula
Sn = a*(1 - r^n)/(1 - r)
We have
- a = 4 = first term
- r = 2, since we want all the terms to be positive
- n = 10 = number of terms to sum up
So,
Sn = a*(1 - r^n)/(1 - r)
S10 = 4*(1 - 2^10)/(1 - 2)
S10 = 4*(1 - 1024)/(-1)
S10 = 4*(-1023)/(-1)
S10 = 4092
Answer:
3/8^3
Step-by-step explanation:
its like 1/2 x 1/2 x1/2 its 1/2^3
or 7x7x7x7x7=7^5 its the same concept....
D is the correct answer luv
Hey there!
Consider the exponential growth equation:

, where:
P = initial amount
r = interest rate (as a decimal, divide a percentage by 100 to get its decimal form)
t = years
All you need to do is plug in your given numbers:
P = 120
r = 0.10
t = x
Your final equation will be:

Hope this helped you out! :-)