Yes it is thirty because when u do 5×2×3 the correct answer turns out to be 30 $o yes!!!!!!
What triangle? Is there one on here?
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
To solve this problem, you can split the shape into a triangle and a parallelogram.
You can do this by imagining/drawing a line from point A to point C>
Now you can work out the area of triangle ACB
1/2 x b x h
1/2 x 5 x 3
= 7.5
Now work out the area of the parallelogram ACDE
b x h
5 x 3 = 15
Add the areas together and then you have the answer
7.5 + 15 = 22.5