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
Ksivusya [100]
2 years ago
10

A) If the 5th term of an A.P. is double the 7th term, show that the sum of the 17 terms zero.​

Mathematics
1 answer:
gayaneshka [121]2 years ago
5 0

Answer:

see explanation

Step-by-step explanation:

The nth term of an AP is

a_{n} = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Given a₅ is double a₇ , then

a₁ + 4d = 2(a₁ + 6d) , that is

a₁ + 4d = 2a₁ + 12d ( subtract a₁ from both sides )

4d = a₁ + 12d ( subtract 12d from both sides )

- 8d = a₁

The sum of n terms of an AP is

S_{n} = \frac{n}{2} [ 2a₁ + (n - 1)d ] , substitute values

S_{17} = \frac{17}{2} ( 2(- 8d) + 16d)

     = 8.5(- 16d + 16d)

     = 8.5 × 0

     = 0

You might be interested in
Louis age is three years more than twice the age of Sánchez . The sun of their ages is 39. How old are Sánchez and Louis ?
Vinvika [58]

Answer:

Sanchez- 42

Louis- 40

Step-by-step explanation:

hope this helps

5 0
3 years ago
Question 1: A certain county has 1,000 farms. Corn is grown on 100 of these farms but on none of the others. In order to estimat
Nina [5.8K]

Answer:

Plan II

Step-by-step explanation:

A certain county has 1,000 farms.

Corn is grown on 100 of these farms but on none of the others.

Since corn is grown on only 100 of these farms, the population of interest is the 100 farms on which corn is grown.

Therefore, a better method for estimating the total farm acreage of corn for the county is Plan II.

a) Identify the 100 corn-growing farms.

b) Sample 20 corn-growing farms at random.

c) Estimate the mean acreage of corn for corn-growing farms in a confidence interval.

d) Multiply both ends of the interval by 100 to get an interval estimate of the total.

4 0
2 years ago
I really need help this is my second time......
KIM [24]
First find the area of the triangle,
(8.4 x 24)/2 = 100.8
Then find the area of the parallelogram,
24 x 12 = 288

Then add both,
100.8+288 = 388.8 yd^2
7 0
3 years ago
There are two approaches to solving the equation -3x + 10 = 4x - 20
pashok25 [27]

Answer:

X =30/7

Step-by-step explanation:

The first way would be something like:

-7x + 10 = -20. The first thing we would do is to subtract 10 from both sides.

Therefore,

-7x+10-10=-20-10

Simplified, we get

-7x=-30

Remove the negative symbols

7x =30

x=30/7

Second example:

10=7x - 20

Add 20 to both sides.

10+20=7x-20+20

Simplified,

30=7x

x = 30/7

4 0
2 years ago
Read 2 more answers
Calculate the following:
I am Lyosha [343]
<span>-11 /7 * 7 /5</span>= -2(1/5)

4 0
3 years ago
Read 2 more answers
Other questions:
  • the african bush elephant weighs between 4.4 tons and 7.7 tons.what are its least and greatest weights rounded to the nearest to
    15·1 answer
  • PLEASE HELP WITH MATH URGENT!!!! WILL GIVE MANY ALL MY POINTS
    14·1 answer
  • the table shows the number of lift tickets and ski rentals sold to two different groups. Is it possible to determine how much ea
    12·1 answer
  • Item 19 A plant has an initial height of 1 inch and grows at a constant rate of 3 inches each month. A second plant that also gr
    8·1 answer
  • WILL AWARD BRAINLIEST (Find the measure of the complement and supplement)
    5·1 answer
  • The width of a rectangle is 11 inches less than its length. Find the dimensions of the rectangle if the area is 80 squares inche
    5·2 answers
  • It costs $0.60 to run a fan for 4 hours. How much does it<br> cost to run the fan for 6 hours?
    7·1 answer
  • Part A: Victor is studying for his Finais. He spends 1/3 of an hour studying for History, 2/3 an hour
    7·1 answer
  • Go step by step to reduce the radical.<br> √ 128<br><br> √16 • √8<br><br> 8 √2<br><br> 8 √4 • √2
    9·1 answer
  • What is the measure of side BC?
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!