Question

Find the value of k such that 3x^2+2kx+x-k-5

Answer 1

k=1 hope this helps!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer 2

Let p( x ) = 3x^2+ 2kx + x - k - 5

= 3x^2 + ( 2k + 1 ) x - ( k + 5 )

compare p( x ) with ax^2 + bx + c

a = 3 , b = 2k + 1 , c = - ( k + 5 )

1 ) sum of the zeroes = - b / a

= - ( 2k + 1 ) / 3

2 ) product of the zeroes = c /a

= - ( k + 5 ) / 3

according to the problem given ,

- ( 2k + 1 ) / 3 = 1/2 [ - ( k + 5 ) / 3 ]

2 ( 2k + 1 ) = ( k + 5 )

4k + 2 = k + 5

4k - k = 5 - 2

3k = 3

k = 3/3

k = 1

I hope this helps you.