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
Marizza181 [45]
3 years ago
13

The 9th term of an arithmetic series is 5/2

Mathematics
1 answer:
Verdich [7]3 years ago
8 0

Answer:

- 8050

Step-by-step explanation:

The n th term of an arithmetic sequence is

a_{n} = a + (n - 1)d

where a is the first term and d the common difference.

We require to find both a and d

Given the 9 th term is 2.5 , then

a + 8d = 2.5 → (1)

Given the sum of the second and fifth term is 27, then

a + d + a + 4d = 27, that is

2a + 5d = 27 → (2)

Multiply (1) by - 2 and add to (2) to eliminate a

- 2a - 16d = - 5 → (3)

Add (2) and (3) term by term

- 11d = 22 ( divide both sides by - 11 )

d = - 2

Substitute d = - 2 into (1) and solve for a

a - 16 = 2.5 ( add 16 to both sides )

a = 18.5

The sum to n terms of an arithmetic sequence is

S_{n} = \frac{n}{2}[ 2a + (n - 1)d ], thus

S_{100} = 50 [ (2 × 18.5) + (99 × - 2) ] = 50(37 - 198) = 50(- 161) = - 8050

You might be interested in
Is 90 one tenth of hundred
ss7ja [257]
Yes 90 is 1/10 of hundred
6 0
3 years ago
1) What is 20% of 20?<br> 2) what is 15 is what percent of 30?<br> 3) 50 is 50% of what?
N76 [4]

Hi there!

The word "of" is the same thing as a multiplication sign.

1)

20% = 0.2

0.2 × 20 = 4


2)

? × 30 = 15

divide each side of the equation by 30

? = 0.5

0.5 = 50%


3)

50% = 0.5

0.5 × ? = 50

divide each side of the equation by 0.5

? = 100


There you go! I really hope this helped, if there's anything just let me know! :)

7 0
3 years ago
Read 2 more answers
8. In the first two basketball games, Lee scored a total of
Ira Lisetskai [31]

Answer:

19

Step-by-step explanation:

40-21+19

5 0
2 years ago
a car that was originally worth 29500$ it depreciates at a rate of 2500$ per year find the value of the car after six years
Triss [41]

Answer:

14,500

Step-by-step explanation: Just took the test.

7 0
2 years ago
At a football stadium, 5% of the fans in attendance were teenagers. If there were 10 teenagers at the football stadium, what was
TiliK225 [7]

Answer:

200 people were at the stadium

Step-by-step explanation:

Let us represent the total number of people at the stadium = x

At a football stadium, 5% of the fans in attendance were teenagers. If there were 10 teenagers at the football stadium

Hence:

5% of total number of people = 10 teenagers

5/100 × x = 10

5x/100 = 10

Cross Multiply

5x = 100 × 10

5x = 1000

Divide both sides by 5

5x/5 = 1000/5

x = 200

The total number of people in the stadium is 200

6 0
3 years ago
Other questions:
  • Need help with this one fast! Thanks.
    15·1 answer
  • Jack had 3 bags of golf balls with b balls in each bag; than his frend gave him 6 more golf balls
    8·2 answers
  • Use the Distributive Property to find the price of 9 CDs that cost $13.99 each.
    10·2 answers
  • What are the factor pairs for 100?
    10·1 answer
  • A lawn company advertises that they can spread 7,500 square feet of grass In 2 1/2 hours find the number of square feet of grass
    14·1 answer
  • Fred has 8 dogs. 3 of the dogs are males and 5 are females. What decimal represents the amount of Fred's dogs that are males? Ex
    14·2 answers
  • Brooke paints the outsides of the square walls and triangular ceilings of her treehouse. What is the area?
    12·1 answer
  • Find each trig ratio
    10·1 answer
  • An angle measures 66.4º more than the measure of its complementary angle. What is the
    12·1 answer
  • In a survey of 2264 adults, 729 say they believe in ufos. construct a 95 confidence interval for the population proportion of ad
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!