Examples with solutions for Series / Sequences: Convert into formula

Exercise #1

80 , 60 , 40 , 20, ...

Express the term-to-term rule of this sequence in terms of n.

Video Solution

Answer

20n 20n

Exercise #2

What is the term-to-term rule of the following sequence?

5, 8, 11

Video Solution

Answer

2+3n 2+3n

Exercise #3

In the drawing, four main structures of the series.

Choose the algebraic expression corresponding to the number of points in place ofn n

Video Solution

Answer

2(n+1) 2(n+1)

Exercise #4

What is the term-to-term rule of the following sequence?

3, 6, 9, 12, ...

Video Solution

Answer

3n 3n

Exercise #5

Given the series whose difference between two jumped numbers is constant:

12,18,24,30,36 12,18,24,30,36

Describe the property using the variable n n

Video Solution

Answer

a(n)=12+(n1)×6 a(n)=12+(n-1)\times6

Exercise #6

What is the term-to-term rule for the sequence below?

2,5,8 2,5,8\ldots

Video Solution

Answer

an=3n1 an=3n-1

Exercise #7

Given the series whose difference between two jumped numbers is constant:

3,6,9,12,15 3,6,9,12,15

Describe the property using the variable n n

Video Solution

Answer

a(n)=3+(n1)×3 a(n)=3+(n-1)\times3

Exercise #8

What is the term-to-term rule for the sequence below?

51,47,43,39 51,47,43,39\ldots

Video Solution

Answer

an=554n an=55-4n

Exercise #9

Given the series whose difference between two jumped numbers is constant:

7,11,15,19,23 7,11,15,19,23

Describe the property using the variable n n

Video Solution

Answer

a(n)=7+(n1)×4 a(n)=7+(n-1)\times4

Exercise #10

21 , 24 , 27 , 30...

Choose the correct term-to-term rule for the sequence above.

Video Solution

Answer

3n+33 -3n+33

Exercise #11

What is the term-to-term rule for the sequence below?

4,3,2,1 -4,-3,-2,-1

Video Solution

Answer

n5 n-5

Exercise #12

What is the term-to-term rule of the following sequence?

8, 6, 4, 2, ...

Video Solution

Answer

2n+10 -2n+10

Exercise #13

In the drawing, four main structures of the series.

Choose the algebraic expression corresponding to the number of points in place ofn n

Video Solution

Answer

n2+1 n^2+1

Exercise #14

What is the term-to-term rule of the following sequence?

13, 16, 19, 22

Video Solution

Answer

3n+10 3n+10

Exercise #15

In the drawing, four main structures of the series.

Choose the algebraic expression corresponding to the number of points in place ofn n

Video Solution

Answer

2(2n1) 2(2n-1)

Exercise #16

In the drawing, four main structures of the series.

Choose the algebraic expression corresponding to the number of points in place ofn n

Video Solution

Answer

2n1 2n-1

Exercise #17

What is the term-to-term rule of the following sequence?

3, 7, 11, 15, ...

Video Solution

Answer

4n1 4n-1

Exercise #18

What is the term-to-term rule for the sequence below?

1,3,7 -1,3,7

Video Solution

Answer

4n5 4n-5

Exercise #19

Given the series whose difference between two jumped numbers is constant:

3,15,27,39,41 3,15,27,39,41

Describe the property using the variable n n

Video Solution

Answer

a(n)=3+(n1)×12 a(n)=3+(n-1)\times12

Exercise #20

7 , 5 , 3 , 1

Express the term-to-term rule in terms of n.

Video Solution

Answer

2n1 2n-1