Question

fiind the value of k,if -2 is a root of the quadratic equation kx2+x-10=0

Answer 1

kx^2+x-10=0
x=-2
so value of x will justify the give quadratic equations
so
k(-2)^2+(-2)-10=0
4K-12=0
4k=12
K=3

Answer 2

$\underline{\bold{Given:-}}$

$k {x}^{2} + x - 10 = 0 \: is \: a \: quadratic \: equation.$

-2 is the root of given quadratic equation.

$\underline{\bold{To\:find:-}}$

The value of k is to be find out.

$\underline{\bold{Solution:-}}$

Since , -2 is the root of given quadratic equation. i.e.,

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

So, x = -2 will satisfy the given equation.

If x = -2

$k { (- 2)}^{2} + ( - 2) - 10 = 0 \\ \\ k(4) - 2 - 10 = 0 \\ \\ 4k - 12 = 0 \\ \\ 4k = 12 \\ \\ k = \frac{12}{4} \\ \\ \boxed{k = 3}$

So, the value of k is 3