Question

If x+2 is a factor of the polynomial x2 + mx + 14 find the valueof m

Answer 1

x+2 is a factor, therefore:

x+2=0

x=-2

Now,

$f(x) = {x}^{2} + mx + 14$

$f( - 2) = {( - 2)}^{2} + m \times - 2 + 14 = 0$

$4 - 2m + 14 = 0$

$- 2m = - 18$

$m = 9$

Answer 2

Answer:

$x + 2 = 0 \\ \\ x = - 2$

is the factor of the given polynomial.

•°•

$x^{2} + mx + 14 = 0$

$( - 2)^{2} + m( - 2) + 14 = 0$

$4 + 14 - 2m = 0$

$2m = 18$

$m = 9$