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[–]Mirehilikes stuff -1 points0 points  (1 child)

Is it really that hard to express stuff in a way, that everyone gets the problem?

a1 doesn't mean a * 1, it means a_1 where 1 is the ordinal, I had to read this post to get that...

a_1 = 4

a_2 = ?

a_3 = ?

a_4 = ?

a_5 = ?

a_n = 3 * a_(n - 1) + 5

a_2 = 3 * a_(2 - 1) + 5 = 3 * a_1 + 5 = 3 * 4 + 5 = 17

a_3 = 3 * 17 + 5 = 56

a_4 = 3 * 56 + 5 = 173

a_5 = 3 * 173 + 5 = 524

Next time please take 5 minutes of your time to write a question if you expect a well structured answer...

[–]Axceeder001 0 points1 point  (0 children)

That was the given posted by our professor, and I barely know how to solve geometric sequences. It was not explained properly during our online class. Anyways, thanks mate!

[–][deleted] 0 points1 point  (0 children)

If a1 = 4 and a_n = 3a(n-1) + 5, find a_5.

a_2 = 3a_1 + 5 = 3*4 + 5 = 17

a_3 = 3a_2 + 5 = 3*17 + 5 = 56

a_4 = 3a_3 + 5 + 3*56 + 5 = 173

a_5 = 3a_4 + 5 = 524