What is the sum of the geometric sequence −4, 24, −144, ... if there are 8 terms?

1 answer:

8 0

The formular for finding the sum of the geometric is: Sn = a1[1 - r^n] /[1 - r]
Where Sn = Number of terms in the series = 8
a1 = the first term = -4
r = common ration = a2/a1 = 24 / -4 = -6.
S8 = -4[1 - [-6]^8 / [1 - (-6)]
S8 = -4 - (1 - 1679616) / 7
S8 = -4 [-1679615] /7
S8 = 6718460 /7 = 959,780.
Therefore, the sum of the first 8 terms in the series is 959,780.

You might be interested in

What is bigger 7/8 or 13/15?

erastovalidia [21]

The answer would be 13/15

8 0

3 years ago

5 cups of water for every 2 cups of cornmeal one sys using 3 cups of water i will need 1 and 1/5 is that correct

Naily [24]

Answer:

yes

Step-by-step explanation:

This is correct because there are 2.5 cups of water per cup of cornmeal.

6 0

4 years ago

What is the Area and perimeter of triangle HAB?

charle [14.2K]

bearing in mind that there are 90 feet between each base in a baseball diamond, so the total perimeter of it will be 90*4 = 360, one third of that is 360/3 = 120.

So Jones went 120 feet first and then another and so on, check the picture below.

using those values, can get the length of those sides, using the pythagorean theorem.

$\bf AH=\sqrt{HF^2+FA^2}\implies AH=\sqrt{9000} \\\\\\ AB=\sqrt{AS^2+SB^2}\implies AB=\sqrt{7200} \\\\\\ HB = AH = \sqrt{9000} \\\\[-0.35em] ~\dotfill\\\\ \stackrel{perimeter}{\sqrt{9000}+\sqrt{7200}+\sqrt{7200}}\qquad \approx \qquad \stackrel{perimeter}{264.57}$

now, we can plug those values in the Heron's Area Formula to get its area.

$\bf \qquad \textit{Heron's area formula} \\\\ A=\sqrt{s(s-a)(s-b)(s-c)}\qquad \begin{cases} s=\frac{a+b+c}{2}\\[-0.5em] \hrulefill\\ a=\sqrt{9000}\\ b=\sqrt{7200}\\ c=\sqrt{7200}\\ s\approx 132.29 \end{cases} \\\\\\ A=\sqrt{132.29(132.29-\sqrt{9000})(132.29-\sqrt{7200})(132.29-\sqrt{7200})} \\\\[-0.35em] ~\dotfill\\\\ ~\hfill A\approx 3337.289~\hfill$

3 0

3 years ago

56of the 90pets in the pet show are cats 4/5of the cats are calico cats. What fraction of the pets are calico cats?

meriva

To get the answer, we can divide 56 by 5 to find one fifth of the cats. Then, we can multiply this number to get four fifths of the cats. Then, we put this number over 90 since there is 90 pets in the entire show. Then, this answer ends up being about half all of the pets are calicos.

4 0

4 years ago

Read 2 more answers

Express in scientific notation. 0.0173

gogolik [260]

The one is in the 1/100 column which is equal to 1/10^2 which is equal to 10^-2.

1.73X10^-2

8 0

3 years ago