Question

if x=-3/2 is root of eqn kx² -10x+30=0,find k​

Answer 1

let x=-3/2, in the eqn

k(9/4)+15+30=0

k=-45×4/9=-5×4=-20

Answer 2

Answer:

Step-by-step explanation:

Given :

To find the value of k,

if x = $\frac{-3}{2}$, is a root of the equation,

⇒ kx² - 10x + 30 = 0

Solution :

Root of the equation = $\frac{-3}{2}$

⇒ $k(\frac{-3}{2})^2 -10(\frac{-3}{2}) + 30 = 0$

⇒ $k(\frac{9}{4}) + (\frac{30}{2}) + 30 = 0$

⇒ $k(\frac{9}{4}) + 15 + 30 = 0$

⇒ $k(\frac{9}{4}) + 45 = 0$

⇒ $k(\frac{9}{4}) = -45$

⇒ $k = -45 \times\frac{4}{9}$

⇒ $k = \frac{-180}{9} = -20$