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
makvit [3.9K]
3 years ago
7

I need to know how to indicate this sum

Mathematics
1 answer:
Triss [41]3 years ago
7 0
Put n = 1

3 - 20 = -17

Put n = 2 ( incremented)

6 - 20 = -14

Put n = 3 ( incremented)

9 - 20  = -11

From the given values deduce a general recurrence relation. The series follow a pattern which is arithmetic sequence pattern.

ao = -17
d = -14 - (-17) = 3
 

S = n/2 (2ao + d(n-1))

n = 20 -1 + 1 = 20 (as you start from 1 not 2)

S = 20/2( 2 * -17 + 3(20-1)) = 230



You might be interested in
A tile store charges $607.50 to install 135 square feet of tile. Assuming they charge the same rate
jasenka [17]

Answer:

the tile is 4.50 per square foot to install

it will cost 3780.00 to install 840 square feet

Step-by-step explanation:

divide 607.50 by 135 to find out the price per square foot to install

multiply the price per square foot by the number of square feet you are installing so 4.50 X 840

7 0
4 years ago
On a DVD, information is stored on bumps that spiral around the disk. There are 73,000 ridges (with bumps) and 73,000 valleys (w
Juli2301 [7.4K]

Answer:

I pretty sure it's 8cm.

Step-by-step explanation:

I multiplied 73,000 by 0.000074, which resulted in 5.402.
Then, I multiplied 73,000 by 0.000032, which resulted in 2.336.
I added the products together, which gave a sum of 7.738.
Then I rounded to the nearest whole number, which is 8, because the tenth in the decimal (.7) rounds up because it is >4.

5 0
3 years ago
Let X and Y again be uniformly distributed independent random variables on [0, 1]. a) Compute the expected value E(XY ). b) What
Mariulka [41]

Answer:

a) Computing the expected value E(XY) gives 1/4

b) The probability density function fZ(z) of Z = XY is calculated in the attached picture.

c) Computing E(Z) gives 1/4

Step-by-step explanation:

Comparing the computation of E(Z) using the answer to b), it shows that the values are equal.

7 0
3 years ago
A wheel has a diameter of 28 inches. What is the approximate distance around the outside of the wheel? Use 3. 14 for pi
KonstantinChe [14]

Answer:

87.92

In this case we're trying to find circumference

Formula: c = pi×d

The problem says to use 3.14 for pi

c = 3.14 × 28 = 87.92

3 0
3 years ago
The cost to a store for an MP3 player is $60. The selling price is $105. A classmate says that the markup is 175% because $105$6
blsea [12.9K]

It is given that the cost price of the MP3 player is $60 and the selling price is $105.

The markup is given by the formula:

Markup = \frac{S.P.}{C.P.} (100)

= \frac{105}{60} (100)

= 1.75 × 100

= 175%

Yes, the classmate is correct.

Hence, the markup is 175% and the classmate is correct.

5 0
3 years ago
Other questions:
  • Find the four digit number in which the first digit is one fourth of the last digit, the second digit is 6 times the first digit
    7·1 answer
  • 2. Ignacio is going on vacation. He needs to drive 479 miles in 7 hours. What is his average speed in miles per
    8·1 answer
  • The angle of depression from the top of a water slide to a pool at the bottom is 13°. If the slide is 60 meters long, how high a
    12·1 answer
  • If $1400 is the selling price and 10% as the profit percentage. What is the cost price and profit?
    6·2 answers
  • Where do i put parantheses into 140/2+12-4x2=2
    10·1 answer
  • Hector is rewriting the expression 7 Superscript 11 in expanded form. How many terms will be multiplied in his rewritten express
    12·2 answers
  • PLEASE HELP I WILL BE PICKING BRAINLIEST
    6·1 answer
  • HELP AND YOU WILL GET BRAINLIEST!!!!!!!!
    6·2 answers
  • Is there a more useful way to display this informa 1-1. BIRTHDAY BONANZA About 18,000,000 people on Earth share your birth date
    9·1 answer
  • What is the rate of change for y= -3x<br> initial value:<br>rate of change:​
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!