Can someone help me with this question? It's in the attachment

Question

unknowshadow · Answer

attachment

karim728 · Answer

1. arithmetric sequence
2. formula --> an= $$28600+1200\times(n-1)$$ and the first 5 ears salary is $$\sum_{1}^{5}(28600+1200\times(n-1))=?$$

mathmale · Answer

I agree with karim that this is an arithmetic sequence.  Beginning with the first year's salary, add $1200 to obtain the 2nd year's salary.  And so on.

Best if you can find the proper formula for this.  Write it out.  In high school I used l=a+(n-1)d.  Have you seen this formula or a similar one?

Helpers:  PLEASE, NO DIRECT ANSWERS!  Thank you.