Question

Determine K, so that k^2+4k+8k,2k^2+3k+6,3k^2+4k+4 are three consecutive terms of an ap .

Answer 1

$( {k}^{2} + 4k + 8k) + (3 {k}^{2} + 4k + 4) = 2(2 {k}^{2} + 3k + 6)$