Tricky maths

[Tridymite]

Can anyone help with this?

Show that the sum between 1 and k of k.3^(3-1) =1/4[(3^k).(2k-1)+1].

[dr b]

can you clarify? what is k.3^(3-1) supposed to represent? 3^(3-1) is just 9.

[Prudie]

Agreed or it could be 3k^2 (3k squared)

[boxtops]

correction from OP here http://www.theanswerb.../Question1129862.html