Question

find the value of k if (x + 3) is a factor of 3x + kx + 6

Answer 1

If x+3 is a factor of the given equation then x = -3 must satisfy the equation.

Substituting the value x = -3 we get,

3(-3)^2 -3k + 6 = 0
3k = 33
k = 11

Answer 2

$\Large{\underline{\underline{\bf{Ello}}}}$

$let \: p(x) = 3 {x}^{2} + kx + 6 \: be \: the \: given \: polynomial. \\ \\ then (x + 3) \: is \: a \: factor \: of \: p(x) \\ \\ p( - 3) = 0 \\ \\ 3 {( - 3)}^{2} + k \times ( - 3) + 6 = 0 \\ \\ 27 - 3k + 6 = 0 \\ \\ 33 - 3k = 0 \\ \\ k = 11 \\ \\ hence \: (x + 3) \: is \: a \: factor \: of \: 3 {x}^{2} + kx + 6 \: if \: k = 11$

$\Large{\underline{\underline{\bf{Thanks}}}}$