Question

VOCALOID ONLY.

Answer 1

Arithmetic Sequence Formula:

an = a1 + (n − 1)d

In this formula, a1 represents the first term of the sequence, n is the position of the term in the sequence, d is the common difference, and an is the desired term of the sequence.

Applying this formula to find the 25th term of the arithmetic sequence 2, 9, 16 … will result in the following.

an=a1 + (n − 1)d

a25=2 + (25 − 1)(7)

a25=2 + (24)(7)

a25=2 + (168)

a25=170 I dont understand o.o

Answer 2

Think about what each term in the formula represents

a1 = first term
an = nth term

d = common difference
n = number of terms

Answer 3

Take the formula and replace the terms with the wpppropriate values from the problem

Answer 4

Appropriate

Answer 5

The first term is 2? o.e

Answer 6

Good keep going

Answer 7

Oh wait an would be 25? o.o

Answer 8

close but not quite

Answer 9

an is the last term. since we don't know it yet we will simply write an = a25

Answer 10

n = number of terms = 25

Answer 11

Ah okie

Answer 12

to find d, consider the pattern of the sequence. each number is the previous number + a common difference

what is the common difference?

Answer 13

The common difference is 7 :O

Answer 14

good now plug everything in

Answer 15

an = a1 + (n − 1)d = ?

Answer 16

[don't change the format/arrangement of the formula, just replace variables with the appropriate values

Answer 17

Is it 2 +(25 - 1)7 o.o I think

Answer 18

good but don't forget the a25 term

Answer 19

a25 = 2 +(25 - 1)7

this matches what you have written above

Answer 20

do you understand the rest of the steps?

Answer 21

an=a1 + (n − 1)d

a25=2 + (25 − 1)(7)

a25=2 + (24)(7)

a25=2 + (168)

a25=170 I dont understand o.o

Answer 22

No maams D:

Answer 23

a25=2 + (25 − 1)(7)

we follow pemdas and work inside the parentheses. 25 - 1 = 24

a25 = 2 + 24(7)

now multiply 24*7 to get 168

a25 = 2 + 168

add 2 + 168 to get 170

a25=170 = last step

Answer 24

the key is to recognize that a25 doesn't mean a*25. "25" is a subscript/label for a

Answer 25

does it make a bit more sense now?

Answer 26

Ah Okie :D Yes ma'am thank you ^.^. I wish they could teach it like this in the lessons