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
sleet_krkn [62]
3 years ago
15

What is the sum of this infinite geometric series

Mathematics
1 answer:
nordsb [41]3 years ago
4 0

You probably know that for |r|, we have

\displaystyle\sum_{i=0}^\infty ar^i=\dfrac a{1-r}

Your sum starts at i=1, so it's equivalent to

\displaystyle\sum_{i=1}^\infty 12\left(\dfrac12\right)^i=\sum_{i=0}^\infty 12\left(\dfrac12\right)^i-12\left(\dfrac12\right)^0=\dfrac{12}{1-\frac12}-12=12

so the answer is A.

You might be interested in
(3x-5)(2x+7)<br> Please show all the work<br> Thank You
dalvyx [7]

(3x-5)(2x+7) =

= 3x·2x + 3x·7 - 5·2x - 5·7

= 6x² + 21x - 10x - 35

= 6x² + 11x - 35

8 0
3 years ago
What is the area of a square with sides of lengths 5/8 inch
expeople1 [14]
 5/8
5*5=25
8*8=64
25/64 inches ^2
5 0
2 years ago
Read 2 more answers
Whoever’s correct i will make their question as brainliest! :) be quick please
Dvinal [7]
Correct answer is 6x^8 y^5 hope it helps
8 0
2 years ago
Can anyone help me here?
Murrr4er [49]

Answer:

3.14 x 4

Step-by-step explanation:

5 0
3 years ago
At the beginning of the year, the ratio of juniors to seniors in high school X was 3 to 4. During the year, 10 juniors and twice
Lady bird [3.3K]

Answer: E. 120

The number of seniors were there in high school X at the beginning of the year = 120

Step-by-step explanation:

Given : At the beginning of the year, the ratio of juniors to seniors in high school X was 3 to 4.

Let the number of juniors be 3x and the number of seniors be 4x.

Since , during the year, 10 juniors and twice as many seniors transferred to another high school, while no new students joined high school X.

i.e. Number of juniors at the end of the year = 3x-10

Number of seniors at the end of the yea = 4x-2(10)=4x-20

At the end of the year, the ratio of juniors to seniors was 4 to 5.

\Rightarrow\dfrac{3x-10}{4x-20}=\dfrac{4}{5}

\Rightarrow5(3x-10)=4(4x-20)

\Rightarrow15x-50=16x-80

\Rightarrow16x-15x=80-50

\Rightarrow x=30

The number of seniors were there in high school X at the beginning of the year = 4(30)=120

Hence, the correct answer is E. 120 .

6 0
3 years ago
Other questions:
  • A store sells four-packs of permanent markers in assorted colors for $3.19 per pack. All spiral-bound notebooks, whether wide-ru
    8·2 answers
  • Math help mee plzzzzzz THERE IS A ATTACHMENT SO WAIT AT LEAST 30 SECONDS PLZZZZ
    5·1 answer
  • Which of the following is a non-repeating, non-terminating decimal?
    12·1 answer
  • Which equations represent the line that is perpendicular to the line 5x – 2y = -6 and passes through the point
    14·2 answers
  • Solve for x: 4 = (-8) +3x. Will you please help?
    10·2 answers
  • Last year Jo paid £245 for her car insurance.
    7·1 answer
  • This line segment will be dilated with the point of dilation at (4,1) and scale factor of 2. What is the x-coordinate of one of
    11·1 answer
  • Help me please?! I’ll give brainliest
    9·1 answer
  • An equation to find the length in centimeters if the width is 10 cm
    13·1 answer
  • 18 x 13 - 8 + 1,387 - 5,800,732,812 x 65
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!