MathematicsIf the sum of the zeroes of the quadratic polynomial 3×2-kx+6 is 3, then find the value of k.

If the sum of the zeroes of the quadratic polynomial $3 x^{2} - kx + 6 is 3$ , then find the value of k.

Given that, sum of zeros of

3 x^{2} - kx + 6 is 3

.
The sum of roots are

- \frac{b}{a}

.
From given equation, comparing with

a x^{2} + bx + c = 0,

we get,

a = 3, b = - k

c = 6

So, the sum of roots =

- \frac{b}{a}

\Rightarrow - \frac{b}{a} = \frac{- (- k)}{3}

\Rightarrow 3 = \frac{k}{3}

\Rightarrow k = 9

Thus, if the sum of zeroes of the quadratic polynomial

3 x^{2} - kx + 6 = 0

3

, then the value of

k = 9 .

Therefore, option (2) is correct.

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