find the value of k given that one solution of the equation is x^2-kx+15=0 is 1/2

Question

find the value of k given that one solution of the equation is x^2-kx+15=0 is 1/2. Answer options are 61/5, 61/2, 20, or -61/4

Answer 1

If x=1/2 is a a solution to

x^2-kx+15=0 

then

1/4-k/2+15=0

k=61/2.