Question

7. What is the value of k if 3 is a
root of 3x^2+(K-B)x+9=0
9
-9
3
-3​

Answer 1

Answer:

Correct Question:

• What is the value of k if 3 is a root of 3x² +(k - 1) x +9

Solution:

• From question, they given that 3 is the root of given polynomial, so p(x) = 0

$: { \implies{ \sf{p(x) = 3{x}^{2} + (k - 1)x + 9 }}} \\ \\ : { \implies{ \sf{p(3) = 3\times {3}^{2} + (k - 1)3 + 9 }}} \\ \\ : { \implies{ \sf{27 + 3k - 3 + 9 = 0}}} \\ \\ : { \implies{ \sf{27 + 6 + 3k = 0}}} \\ \\ : { \implies{ \sf{33+ 3k = 0}}} \\ \\ : { \implies{ \sf{3k = - 33}}} \\ \\ : \implies{ \sf{k = \frac{ - 33}{3} }} \\ \\ : { \implies{ \sf{k = - 11}}}$

Therefore,

• Value of k is -11

${ \mathbb{ \red{MARK \: AS \: BRAINLIEST...! :) }}}$