Question

If the sum of zeros of the polynomial 3x square - kx + 6 is 3 then find the value of k.

Answer 1

Given: We are given,that the sum of zeros of the polynomial $\sf{3{x}^{2}-kx+6}$=3.

Need to find: The value of k = ?

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GivEn:

• In a general Quadratic equation of a form $\sf{a{x}^{2}+bx+c=0}$sum of roots are by $\sf\dfrac{-b}{a}$

In the given Quadratic equation,

$\sf{3{x}^{2}-kx+6}$=3.

where,

• a = 3
• b = -k
• c = 6

$\sf \: sum \: of \: roots = \frac{ - b}{a} = \frac{ - ( - k)}{3} = \frac{k}{3}$

and sum of roots is given 3

$\sf \implies \: \frac{k}{3} = 3 \\ \\ \sf \implies{\boxed{\sf{k = 9}}}$