Question

Find k given that 3k + 1, k and -3 are consecutive terms of an arithmetic sequence.

Answer 1

Since the terms are consecutive, k -(3k + 1) = - -3 - k {equating difference }
$\therefore k-3k-1=-3-k$
$\therefore -2k-1=-3-k$
$\therefore -1=3=-k+2K$
$\therefore k=2$