Question

a theater has 43 seats in the first row, 45 seats in the second row, 47 seats in the third row, and so on.
is it arithmetic or geometric?
a^n=?
there are ? seats in row 17?

Answer 1

it's arithmetic because the terms have a common difference (2, in this case).

Answer 2

i never saw a question like this before i do not understand

Answer 3

so how do i solve for a^n=
and how manyseats

Answer 4

i ask my substitute teacher and she dont know ??? clueless

Answer 5

Does the problem tell you how many total rows there are?

Answer 6

it says how many seats are there in row 17?

Answer 7

write a general term for sequence a^n

Answer 8

Row 3 has 47 seats, so Row 17 has 47 + (14*2). that is the third row, plus fourteen times (17-3) the difference between the rows. So Row 17 has 75 seats.

Answer 9

The formula for the general term is: a1 + (n-1) d

this is the first term + (the term number - 1)*difference

Answer 10

ok so for a^n= 47+(14*2) for the term

Answer 11

For row 17, = 43 +(17-1)*2

Answer 12

which is just plugging the numbers into the an=a1+(n-1)d

also it's not a^n, remember the n is subscript, not like a power. :)

Answer 13

ok i see how you gather the information to get 17 =75 seats

Answer 14

thank you and i am still veiwing this formula

Answer 15

No problem. Keep the formula in mind as it's going to come useful all the time with sequences.

Answer 16

i need this as a note to show to the class becuase this substitute teacher slow