One of the roots of the equation $$x^2 – 12x + k = 0$$​ is x = 3. The other root is _____________.

Correct option is B

Given:

- The equation is $$x^2 - 12x + k = 0$$​​
- One root is x = 3

Concept Used:

For a quadratic equation $$ax^2 + bx + c = 0$$​ , the sum and product of the roots are:
Sum of roots  = $$-\frac{b}{a}$$​​
Product of roots  = $$\frac{c}{a}$$​​
Here, a = 1 , b = -12 , and c = k

Solution:

Sum of roots  =  $$-\frac{-12}{1} = 12$$​​

Let the other root be $$\alpha$$  Since one root is x = 3 , we have:
​$$3 + \alpha = 12 \\\ \\ \alpha = 12 - 3 = 9$$​​

Answer: The other root is x = 9