Question

If one of the zeroes of the quadratic polynomial 2x 2 + kx-10 is -4, find K

Answer 1

Let p(x)=2x²+kx-10
If -4 is one of the zeros of p(x).
Then, p(-4)=0
Putting x=-4
2(-4)²+k(-4)-10=0
32-4k-10
22=4k
11/2=k
5.5=k