Question

Find an equation for the nth term of the arithmetic sequence.

a19 = -58, a21 = -164

Answer 1

spose you normalize it to:

b0 = a19 and b2= -164

Answer 2

or

a21 = a19 + 2d , solve for d to find the common difference

then using either value, subtract how many differences it takes to get to the first term

Answer 3

Sorry my internet went out. @amistre64
So far I've gotten -53. I don't know what to do next.

Answer 4

Answer choices:
an = 896 - 53(n - 2)
an = 896 - 53(n - 1)
an = 896 + 53(n + 1)
an = 896 - 53(n + 1)

Answer 5

when given options, the simplest thing to do is to test them out ... which one gives us the correct values when n=19 and 21?

Answer 6

they all start with 896, and all have a 53

we know we get lower so -53 is required

and the proper format is that for a given n value, we assess it at the one before it, the n-1th value

Answer 7

so it would be an = 896 - 53(n - 1)

Answer 8

that would be the one

Answer 9

896-53(20)=-164

Answer 10

Thanks