Question

16. If x=2 is a root of the following equation,
find the value of k. Also find the other root of
the equation
3x^2 - kx - 2 = 0​

Answer 1

Step-by-step explanation:

given x=2

by putting the value of x we get

3x(2)²-kx2-2=0

12-2k-2=0

10-2k=0

5-2k=0

k=5/2

equation becomes 3x²-5x-2 =0

by splitting middle terms

3x²-6x+x-2 =0

3x(x-2)+1(x-2)

(3x+1)(x-2)=0

other root is -1/3

Answer 2

Given:-

=> x=2 is root of 3x²-kx-2=0

To find :-

=> value of k and other root

Solution:-

X=2 , put the value of x on given equation, we get

=> 3×(2)²-k×2-2=0

=> 3×4-2k-2=0

=> 12-2-2k=0

=> 10=2k

=> k=5

So put the value of k on given 3x²-kx-2=0,we get

=> 3x²-5x-2=0

factories the equation:-3x²-5x-2=0

=> 3x²-6x+x-2=0

=> 3x(x-2)+(x-2)=0

=> (3x+1)(x-2)=0

=> 3x+1=0 and x-2=0

=> x= -1/3 and x=2

Answer:- other zero is -1/3 and k=5