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
Varvara68 [4.7K]
3 years ago
5

The first element in an arithmetic sequence is 2. Its twenty second is 14. Find the value of n so that a(n)=6

Mathematics
1 answer:
Aleks04 [339]3 years ago
8 0

Answer:

<h2>n = 8</h2>

Step-by-step explanation:

Given the nth term of an arithmetic sequence to be Tn = a+(n-1)d

a = first term of the sequence

n = number of terms

d = common difference.

Given the first element a = 2 and 22nd to be 14

T22 = a+(22-1)d = 14

a+21d = 14

Substtuting a = 2 into the equation to get d

2+21d = 14

21d = 12

d = 12/21

d = 4/7

The nth term of the sequence given a = 2 and d = 4/7 will be expressed as;

Tn = 2+(n-1)4/7

Given Tn = 6

6 = 2+(n-1)4/7

6 = 2+4/7 n - 4/7

6-2+4/7 = 4/7 n

32/7=4/7 n

32 = 4n

n = 32/4

n = 8

You might be interested in
There are more than 15 shapes all together but no more than 25. There are 6 more squares than circles. There are 7 fewer circles
Ugo [173]

Answer:

the number of circles is 3

the number of square is 9

the number of triangle is 10

Step-by-step explanation:

Let the number of square = s

let the number of circle = c

let the number of triangle = t

let the total number of the shapes = y

15 < y < 25

y = s + c + t ---- (i)

s = c + 6 ------ (ii)

c + 7 = t ------ (iii)

y = (s) + (c) + (t)

y = (c + 6) + (c) + (c + 7)

y = 3c + 13

15 < y < 25

15 <  3c + 13  < 25

15 - 13 < 3c < 25 -13

2 < 3c < 12

2/3 < c < 12/3

0.67 < c < 4

Thus, number of circle is greater 1 but less than 4

c = 3

s = 3 + 6 = 9

t = 3 + 7 = 10

7 0
4 years ago
What is the value of 4(x - 2)(x + 3) + 7(x - 2)(x - 5) - 6(x - 3)(x - 5) when x = 5?
adelina 88 [10]

Answer:

96

Step-by-step explanation

4(x - 2)(x + 3) + 7(x - 2)(x - 5) - 6(x - 3)(x - 5)

4(5 - 2)(5 + 3) = 12(8) = 96

7(5 - 2)(5 - 5) = 0

- 6(5 - 3)(5 - 5)= 0

96+0-0 = 96

7 0
3 years ago
The graph displays the total cost when buying gas by the gallon. Which statement best describes the relationship between cost an
aivan3 [116]
A) The more gas you buy, the more it costs.
3 0
4 years ago
Suppose someone gives you 6 to 1 odds that you cannot roll two even numbers with the roll of two fair dice. This means you win 6
fiasKO [112]

Answer:

0.75 ;

150

Step-by-step explanation:

Probability of rolling two even numbers :

{1, 2, 3, 4, 5, 6}

P(even) = 3 / 6 = 1/2

From a roll of 2 dice :

P(even) * P(even) = 1/2 * 1/2 = 1/4 = 0.25

P(not even) = 1 - 1/4 = 3/4

X : ____ 6 _______ - 1

P(x) ____ 0.25 ____ 0.75

Expected value :

Σx*p(x) = (6*0.25) + (-1 * 0.75)

= 1.50 - 0.75

= 0.75

If 200 games are played :, n = 200

Expected value * n

0.75 * 200

= 150

5 0
3 years ago
Show that y=2e^(−x) cos(x)−e^(−x) sin(x) is a solution to y''+2y'+2y=0.
lara31 [8.8K]

Answer:

see below

Step-by-step explanation:

y' = -2e⁻ˣcos(x) -sin(x)2e⁻ˣ +e⁻ˣsin(x)-cos(x)e⁻ˣ = e⁻ˣ(-2cos(x)-2sin(x)+sin(x) -cos(x))

=e⁻ˣ(-3cos(x)-sin(x))

y'' = -e⁻ˣ(-3cos(x)-sin(x)) + (3sin(x)-cos(x))e⁻ˣ

y'' = e⁻ˣ[3cos(x)+sin(x) + 3sin(x)-cos(x)] = e⁻ˣ[2cos(x)+4sin(x)]

y''+2y'+2y = 0

e⁻ˣ[2cos(x)+4sin(x)] + 2[e⁻ˣ(-3cosx-sinx)] + 2[2e⁻ˣ cos(x)−e⁻ˣ sin(x)]

e⁻ˣ[2cos(x)+4sin(x)-6cos(x)-2sin(x)+4cos(x)-2sin(x)]

e⁻ˣ[-4cos(x)+2sin(x)+4cos(x)-2sin(x)]

e⁻ˣ[0cos(x)+0sin(x)] = 0

4 0
4 years ago
Read 2 more answers
Other questions:
  • Find the sixth term of the sequence A(n)=6+(n-1)(-2)
    11·1 answer
  • Joey wants to buy strawberries and raspberries to bring to a party strawberries cost $1.60 per pound and raspberries cost $1.75
    5·1 answer
  • Is this a right triangle??? Show work
    9·1 answer
  • Find the value of x.
    10·1 answer
  • Computer monitors are measured by length of the screens what is the save of the tv is the sides ar 38 and 28.5
    11·1 answer
  • Help me please its simple loool<br><br> which one is it
    12·2 answers
  • Use long division to convert the rational number 4/9 to its equivalent decimal form. Upload a document showing all your work.
    7·2 answers
  • Question is attached.<br>NO SPAM ALLOWED!<br>Step by step explanation needed!​
    9·2 answers
  • help please, this is a khan assignment i can't figure out how to word it but i have screenshots that explains everything
    11·1 answer
  • Equations, graphs, Slopes and y-intercepts : application
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!