Question

If one of the roots of quadratic equation X2 – kX + 27 = 0 is 3 then find

the value of ‘k’.​

Answer 1

Answer:

• The value of k is 12.

Step-by-step explanation:

Given that:

Quadratic equation.

• x² - kx + 27 = 0
• One of its root = 3

To Find:

• The value of k.

Concept:

• For finding the value of k we have to substitute the value of one of the root of the quadratic equation in that equation after solving the equation we will get the value of k.

Finding the value of k:

In the given quadratic equation.

⟶ x² - kx + 27 = 0

Substituting one of its root.

⟶ (3)² - k(3) + 27 = 0

⟶ 9 - 3k + 27 = 0

⟶ 36 - 3k = 0

⟶ 3k = 36

⟶ k = 36/3

⟶ k = 12

∴ The value of k = 12

Answer 2

Question:-

• If one of the roots of quadratic equation x² - kx + 27 = 0 is 3 then find  the value of ‘k’.​

To Find:-

• Find the value of k.

Solution:-

Given ,

• One of root of the equation is 3.

Let the value of x is 3

$\longrightarrow\sf \: { 3 }^{ 2 } - 3k + 27 = 0$

$\longrightarrow\sf \: 9 - 3k + 27 = 0$

$\longrightarrow\sf \: 36 - 3k = 0$

$\longrightarrow\sf \: 3k = 36$

$\longrightarrow\sf \: k = \cancel\dfrac { 36 } { 3 }$

$\longrightarrow\sf \: k = 12$

Hence ,

• The value of k = 12