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
Allisa [31]
3 years ago
14

What is the sum of a 56-term arithmetic sequence where the first term is 6 and the last term is 391?

Mathematics
2 answers:
Sati [7]3 years ago
7 0
S_n=\dfrac{a_1+a_n}{2}\cdot n\\\\a_1=6;\ n=56;\ a_{56}=391\\\\subtitute\\\\S_{56}=\dfrac{6+391}{2}\cdot56=\dfrac{397}{2}\cdot56=397\cdot28=11,116
klio [65]3 years ago
4 0

Answer:

The sum of 56 term is 11,116

B is correct.

Step-by-step explanation:

Given:

First term , a=6

Last term l=391

n=56

Formula: Sum of nth term of Arithmetic series.

Sum=\dfrac{n}{2}(a+l)

Substitute the value of a, l and n into formula.

Sum=\dfrac{56}{2}(6+391)

Sum=11,116

Hence, The sum of 56 term is 11,116

You might be interested in
Given the foci of (8,0) and the difference of the focal radii = 6, find the equation of the hyperbola
k0ka [10]

Given :

The foci of hyperbola are (8,0) and (-8,0) .

The difference of the focal radii = 6.

To Find :

The equation of the hyperbola.

Solution :

We know, distance between foci is given by :

2c = 8 - (-8)

c = 8

Also, difference between the foci or focal distance is given by :

2a = 6

a = 3

Now, we know for hyperbola :

b^2 +a^2 = c^2\\\\b^2={c^2-a^2}\\\\b^2 = 64-9\\\\b^2 = 55

General equation of hyperbola is :

\dfrac{x^2}{a^2}+\dfrac{y^2}{b^2}=1\\\\\dfrac{x^2}{9}+ \dfrac{y^2}{55}=1

Hence, this is the required solution.

3 0
3 years ago
Solve the systems using substitution.<br><br> − 2x − 5y = − 5<br> x = 5y − 20
Law Incorporation [45]
-2(5y-20) - 5y = -5
-10y + 40 - 5y = -5
-15y + 40 = -5
-15y = -45, y = 3
x = 5(3) - 20
x = 15 - 20, x = -5
Solution: x = -5, y = 3... or (-5,3)
7 0
3 years ago
5 : 2 : 11 =.... : 6 : ....
lubasha [3.4K]
5:2:11=15:6:33
Multiply by 6/2=3
7 0
3 years ago
Which is a prime number 14,13,21,33
Cloud [144]
13. Because it can't be divided by a whole number except 1 and itself. 14 can be Divided by 2. 21 and 33 can be divided by 3 making them composite or divisible by more than just 1 and itself :)
6 0
3 years ago
Ryan had 4 pieces of pipe that were each 1 1/3 yd long. He also had a piece of wood that was 4 1/6 yd long. Ryan needed to cut t
Andru [333]
4 pieces  of pipe,

4/3 yd long

25/6 yd long

5 pieces same length.

(25/6)/5 = 5/6 yd  is the length of each piece of woods.



3 0
3 years ago
Read 2 more answers
Other questions:
  • What reason explains why the m &lt; Q=115
    5·1 answer
  • Find the quotien of 26,234 divide 42
    11·1 answer
  • Analyze the graph of the quadratic function that contains the points (0,-2), (1,0) and (3,10). Create the equation of the functi
    12·2 answers
  • Please help! John-Mark recorded the stats for several baseball pitchers. He made a scatterplot showing the
    12·1 answer
  • What is the fraction of 1578
    5·2 answers
  • Which paint costs the most per quart? TWO pints = ONE quart FOUR quarts = ONE gallon
    8·1 answer
  • Please can someone solve thiss !!! T~T
    10·2 answers
  • PLEASE HELP ASAP PLEASE
    11·1 answer
  • Alexa borrows $10,000 from her aunt and they agree Alexa will pay her back including 5% simple interest. How much interest will
    7·1 answer
  • I dont understand nothing for math because they teach us hard ways to do it even tho that's how u actually have to do it
    8·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!