Question

if the sum of zeroes of 3x^2-kx+6 is 3 the value of k is ​

Answer 1

Given:- sum of zeroes of 3x^2-kx+6 is 3.

To Find:- value of k.

Solution:-

As we know that sum of zeroes of an polynomial is equal to the -b/a.

By comparing 3x^2-kx+6 to basic polynomial equation ax²+bx+c, we will get a=3, b=(-k) and c=6.

So, according to the problem given,

-b/a = 3x² -kx + 6

-b/a = 3

-( -k ) / 3 = 3

k / 3 = 3

k = 9

Therefore, the value of k is 9.

Answer 2

Given:-

• equation = 3x²-kx+6
• product of zeroes = 3

To find:-

• value of k

Formula to be used:-

$\underline{\boxed{\sf sum \: of \: zeroes = \dfrac{-b}{a}}}$

Solution:-

$\longrightarrow$ sum of zeroes = $\sf\dfrac{-b}{a}$

$\longrightarrow$ 3 = $\sf\dfrac{-(-k)}{3}$

$\longrightarrow$ 3×3 = k

$\longrightarrow$ k = 9.

Additional information:-

$\underline{\boxed{\sf product \: of \: zeroes = \dfrac{c}{a}}}$