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:
shop b
Step-by-step explanation:
We can find for example how much 100 grams of peanut butter cost in each shop using a proportion
shop A 100 : 250 = x : 325
x = (325 * 100) / 250 = $130
shop B 100 : 340 = x : 408
x = (408 * 100)/ 340 = $120
We discovered that shop B is cheaper
Answer:
44
Step-by-step explanation:
Answer:
I think it's c
Step-by-step explanation:
9514 1404 393
Answer:
x = -4
Step-by-step explanation:
The axis of symmetry is the vertical line through the vertex. The vertex is the turning point, or minimum, of the function. It is (x, y) = (-4, 0). The x-coordinate there is -4, so the equation of the axis of symmetry is ...
x = -4
