Answers:
x = -8/5 or x = 8/5
Sum of the first ten terms where all terms are positive = 4092
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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.
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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
Approximately after 15 minutes.
EXPLANATION
The growth rate of the first bacteria is
The growth rate of the first bacteria :
To find the time that, there will be an equal number of bacteria, we equate the two equation;
We solve for t to get,
Or
We discard the negative value.
This implies that,
Answer:
2,436
Step-by-step explanation:
Answer: Fish A: 9 inches ; Fish B: 6 inches
Step-by-step explanation:
This can be turned into a systems of equation, where x equals the length of fish A and y equals the length of fish B:
3x + 2y = 39 → -3x - 2y = -39
3x + 4y = 51 → 3x +4y = 51
Combine: 0 + 2y = 12 → y = 6 inches.
Plug back in: 3x + 2(6) = 39 → 3x = 27 → x = 9 inches.
Answer:
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