1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
laila [671]
3 years ago
11

Find the sum of a finite geometric sequence from n=1 to n=8, using the expression -2(3)^n-1

Mathematics
1 answer:
MissTica3 years ago
8 0
\bf \qquad \qquad \textit{sum of a finite geometric sequence}
\\\\
S_n=\sum\limits_{i=1}^{n}\ a_1\cdot r^{i-1}\implies S_n=a_1\left( \cfrac{1-r^n}{1-r} \right)\quad 
\begin{cases}
n=n^{th}\ term\\
a_1=\textit{first term's value}\\
r=\textit{common ratio}
\end{cases}
\\\\\\
\sum\limits_{n=1}^{8}~-2(3)^{n-1}~~
\begin{cases}
n=8\\
a_1=-2\\
r=3
\end{cases}\implies S_8=-2\left( \cfrac{1-3^8}{1-3} \right)
\\\\\\
S_8=\underline{-2}\left( \cfrac{1-6561}{\underline{-2}} \right)\implies s_8=1-6561\implies S_8=-6560
You might be interested in
Can someone help me<br> Please
VikaD [51]

Answer:

a) 12:45pm

b) 7:30pm

c) 20 15

d) 00 00

4 0
2 years ago
Jessica has an account with a credit union. Her account earns 2.2% simple interest yearly. Exactly a year and a half ago, she op
Sergeu [11.5K]
Interest earned= \frac{PRT}{100}
I=\frac{900*2.2*1.5}{100}
I= <span>$ 29.70</span>
6 0
3 years ago
1. Find the product of 2.6 x 107 and 6.3 x 16
qaws [65]

Answer:

28'042.56

Step-by-step explanation:

2.6 x 107=278.2

6.3 x 16= 100.8

278.2x100.8=28'042.56

7 0
3 years ago
Read 2 more answers
Determine if the function is linear or nonlinear . EXPLAIN​
nordsb [41]

Answer:

it is not linear

Step-by-step explanation:

Linear function means that same increments in x yield uniform increments in y.

First 2 lines: x grows from -5 to 0, so increment in x is 5. For said interval, y grows from 3 to 7, so increment in y is 4.

Then, x grows from 0 to 5, so increment in x is again 5. Now, for the same increase of x, y grows from 7 to 10, so increment now in y is 3.

In the first "5" interval of x, y grew 4, and in the second "5" interval of x y grew 3 ⇒ it is not linear.

The function would have been linear, if last y value had been 11.

5 0
3 years ago
The width of a rectangle is 8 inches shorter than its length. The perimeter of the rectangle is 18 inches. What are the length a
VashaNatasha [74]

Answer:

B

Step-by-step explanation:

Let length be l

Width, w=l-8

Perimeter = 2(l+w) = 2l+2w

2l+2(l-8)=18

6 0
3 years ago
Other questions:
  • Write the equation in slope intercept form of the line that is perpendicular to y=-3x+7 and passes through the point (6,-4)
    7·2 answers
  • Fill in the missing values to make the equations true.
    5·1 answer
  • What is the area of trapezoid QRST?<br>​
    6·2 answers
  • Calcula la suma de los ángulos internos de los siguientes polígonos:
    11·1 answer
  • The length of a rectangle is 5 less than twice its width. The perimeter is 26 meters. Find the dimensions of the rectangle.​
    12·1 answer
  • Y=30x+1 what is the answer to this
    8·1 answer
  • Salma bought  n  packs of pencils. Each pack has  15  pencils. Write an equation to represent the total number of pencils  p  th
    8·1 answer
  • At a restaurant, you buy a combo meal for $7.50. You also want an ice cream sundae for dessert for $3.00. You brought $10 in cas
    15·2 answers
  • Calculate the radius of a circle whose area is equal to the sum of the areas
    11·1 answer
  • What’s 2+2+2+2+2+2+2+2
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!