Question

One of the roots of the equation 2x²–5x+k = 0 is 3. Find the value of K ​

Answer 1

Step-by-step explanation:

Substitute x =3 in the given equation

2(3x3)-5(3)+k=0

2x9-15+k=0

18-15=-k

3=-k

k=-3

The value of K is -3

Answer 2

Answer:

value of k =-1,

value of k = -1,other zero = 5/2

Step-by-step explanation:

let p(x)=2x²+kx-15,

give 3 is one zero of p(x).

Then,

p(3)=0

=> 2(3²)+k(3)-15=0

=>18+3k-15=0

=>3k+3=0

=>3k=-3

divide each term by 3, we get

=>k=-1

put k =-1 in p(x), we get

2x²-6x+5x-15

=2x(x-3)+5(x-3)

=(x-2)(2x-5)

take 2x-5=0

=>x=5/2

therefore,

value of k = -1,

other zero = 5/2

hope this is help full to you