Question

S15 =121,5, a15 = 11,6 ​

Answer 1

Ответ на картинке ✔️

Тема честно не сложная, при прохождении дают 2 нужных формул)

Answer 2

It seems like you've provided two sequences, S15 and a15, but it's not entirely clear what you want to know about them.

S15 appears to be a sequence of numbers starting with 121 and possibly increasing by a constant difference or following a specific pattern. However, I would need more information about the pattern or rule governing this sequence to provide further details.

a15 seems to be another sequence, starting with 11.6, but like the previous sequence, I would need more information about the pattern or rule governing it to provide additional information.

If you could clarify what you're looking for or provide more context about these sequences, I'd be happy to help further.