Question

find the value of k if -5 is one of the roots of the quadratic equation x2 _KX+10=0​

Answer 1

Given equation

$x^{2} -kx+10=0$

-5 is the zero of the polynomial

Substituting x = -5 in the given equation, we get,

$\implies (-5)^{2} -k(-5)+10=0$

$\implies 25+5k+10=0$

$\implies 5k+35=0$

$\implies 5k=-35$

$\implies k = \dfrac{-35}{5}$

$\implies k = -7$

$\boxed{\boxed{\bold{Therefore, \ the \ value \ of \ k \ in \ the \ given \ equation \ is \ -7}}}}$

                                                     

Answer 2

x^2 - kx + 10

x = -5

(-5)^2 - k(-5) + 10 = 0

25 +5k +10 =0

35 + 5k =0

5k = -35

k = -35/5

k = -7

I think this is the answer.......I hope it helps you