Question

What is the 56th term of the sequence below?

-29,-29,-25,-21,-17......

Answer 1

The formula for this is a_n=a_1+(n-1)d. So the numbers into that.

Answer 2

\[a _{n}=a _{1}+(n-1)d\]

Answer 3

im sorry im not good at this can u explain

Answer 4

a_n is the term you are trying to find and a_1 is the first term. d is the difference between the numbers.
Just to be sure, there are not two -29s at the beginning of the sequence right

Answer 5

ok yes
thank you

Answer 6

this should make the equation
\[a _{56}=-29+(n-1)(-4)\]

Answer 7

Then, solve

Answer 8

56?

Answer 9

Sorry, i gave you the wrong formula. Sorry, it is really
S_n = n/2 [2a_1 + (n – 1)d]
The reason is because you dont know the last term

Answer 10

Does it say how many terms are in the sequence?

Answer 11

oh ok so N would be 56 right?

Answer 12

A is -29 right?

Answer 13

i dont know what d would be

Answer 14

Never mind, I gave you the right equation first. n would be 56 because that could be the last term. It doesn't matter. I am sorry, I just learned this and I am trying to get better practice

Answer 15

what would D be?

Answer 16

d is 4 because -25-(-29) is -25+29 which is 4
a56=−29+(56−1)(4)
a56=-29+220
a56=191

Answer 17

thank you so much

Answer 18

Sorry about the confusion :(

Answer 19

its fine!! :)