Question

In a sequence, we know that t(11)= 22. We also know that the common difference is -4.

What is t(13)?


t(13) = ______

Answer 1

t(13) = 14

Explanation:

Given t(11) = 22 and d = - 4

Then to obtain the next term in the sequence subtract 4 from the previous term, that is

f(12) = f(11) - 4 = 22 - 4 = 18

t(13) = t(12) - 4 = 18 - 4 = 14

Answer 2

Explanation:

I hope this means t_11 = 22

If it means t(11) = mx + b where x winds up being 11 and t(x) = 22, we have an entirely different problem. I'll try them both

t_11 = 22

t_11 = 22

d = - 4

what is a (where does this thing start).

L = a + (n - 1)*d

22 = a + (11 - 1)*-4

22 = a + 10*-4

22 = a - 40

a = 62

So finding t(13) is

L = 62 + (13 - 1)*-4

L = 62 + 12 * - 4

L = 62 - 48

L = 14

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I think this is the only way to interpret it. If you get an answer explaining it, I'd take that answer.