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If $x = 3$ is a solution of the equation $3 x^{2} + (k - 1) x + 9 = 0$ then $k$ is

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-13

-11

answer is B.

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Detailed Solution

Given quadratic equation is,

3 x^{2} + (k - 1) x + 9 = 0

.
And

x = 3

is a solution of given equation.
We know that,
If

x = m

is a solution of the equation

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

then

a m^{2} + bm + c = 0

.
At

x = 3

3 {(3)}^{2} + (k - 1) 3 + 9 = 0

⟹ 27 + 3 k - 3 + 9 = 0

⟹ 3 k + 6 + 27 = 0

⟹ 3 k + 33 = 0

⟹ 3 k = - 33

∴ k = - 11

Therefore, the value of

k = - 11

.
Hence, the correct option is 2.

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