Question

One of the roots of the equation
$3 {x}^{2} - kx + 8 = 0$
is
$\frac{2}{3}$
then find the value of k.​

Answer 1

AnsWer :

k = 14.

GiveN :

• 3x² - kx + 8 = 0.
• One of the roots be 2 / 3.

To FinD :

The value of k.

SolutioN :

We have, Equation.

3x² - kx + 8 = 0.

☛ Compare With General Equation.

ax² + bx + c = 0

Where as,

• a = 3.
• b = k.
• c = 8.

$\rule{90}2$

» Now,Putting the value of x = 2 / 3.

→ 3x² - kx + 8 = 0.

→ 3( 2 / 3 )² - k ( 2 / 3 ) + 8 = 0.

→ 3* 4 / 9 - 2k / 3 + 8 = 0.

→ 4 / 3 - 2k / 3 + 8 = 0.

→ 4 / 3 - 2k / 3 = - 8.

→ 4 - 2k = - 24.

→ - 2k = - 28.

→ k = 14.

✡ Therefore, the value of k is 14.