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
navik [9.2K]
3 years ago
15

If the sum of first 9 terms of an A.P is equal to sum of its first 11 terms, then what is the sum of its 20 terms?

Mathematics
2 answers:
iVinArrow [24]3 years ago
5 0

Answer:

Put the values into the formula....let me know if you need help....

Step-by-step explanation:

Mamont248 [21]3 years ago
3 0

Answer: 0

Step-by-step explanation:

Sum of the first 9 terms = 9/2 (2a + 8d)

Sum of the first 11 terms = 11/2 (2a + 10d)

S9 = S11

9a + 36d = 11a + 55d

2a = -19d

2a + 19d = 0...........(1)

S20 = 20/2 (2a + 19d)

= 20/2 (0) . .. ............from (1)

S20 = 0

You might be interested in
The lemonade stand at the county fair sells the lemonade at a price of two cups for $3.60. Complete the table at right to find w
kakasveta [241]
$3.60 for 2 cups would be $1.80 for one cup.

$3.60 for 2

$5.40 for 3

$7.20 for 4

$9 for 5

$10.80 for 6

$12.60 for 7

$14.40 for 8



4 0
2 years ago
Please help!! Will mark first answerer brainiest​!! Thank you so much!
Mrac [35]
The answer is C i believe, always remember to add alike terms. 
8 0
3 years ago
Read 2 more answers
1/3x + 8x^4 - 2/3x^2 - x in standard form
leva [86]

Answer:

8x^{4}-2/3x^{2}-2/3x

Step-by-step explanation:

8 0
3 years ago
Helpppppp. Pleaseeeeeeeeeeee
Irina-Kira [14]
I think it’s 0.85d, but i’m not sure
7 0
3 years ago
2 + 10n + 9 + 6n <br><br><br> Explain please
marshall27 [118]

Answer:

11 + 16n

Step-by-step explanation:

Collect the like terms

2 + 9 = 11
10n + 6n = 16n

11 + 16n is the final answer, and cannot be simplified further

5 0
2 years ago
Read 2 more answers
Other questions:
  • A circle has center at (7, 0). What is the equation of the line that is tangent to the circle at (2, 0)?
    14·1 answer
  • Geometry question helpppppppp
    6·1 answer
  • A rectangle has an area of 20 square feet a similar rectangle has an area of 180 square feet what is ratio of the areas of these
    6·1 answer
  • What is not equivalent to 65%
    14·2 answers
  • PLEASE HELP GEOMOTRY
    7·2 answers
  • Can someone help me find the area of this thx
    6·2 answers
  • By what percent will the fraction change if its numerator is increased by 25% and its denominator is increased by 20%
    14·1 answer
  • Evaluate 4+(m-n) to the fourth power when m=7 and n=5
    9·1 answer
  • Plz help will make the Brainly
    12·1 answer
  • Less than a number is 18. What is the number (n)?
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!