Question

If 3 is a root of the quadratic equation is x^2-kx+42=0 find the value of k and the other root of the equations

Answer 1

Answer:

k = 17

Step-by-step explanation:

Given,

3 is a root of the quadratic equation x^2 - kx + 42 = 0

To Find :-

value of 'k'

Solution :-

As '3' is the roots of the quadratic equation we can substitute in the place of 'x' in the quadratic equation :-

$(3)^2-k(3)+42-0$

9 - 3k + 42 = 0

51 - 3k = 0

51 = 3k

k = 51/3

= 17

∴ Value of 'k' = 17