What is the positive value of k if difference of roots of the quadratic equation x2 – kx + 12 = 0 is 1?

-7,because it has been verified also:

x2-(-7)x + 12=0

x2+7x +12=0

x2+4x +3x +12=0

x(x+4)+3(x+4)=0

(x+3)(x+4)=0

now,difference= -3-(-4)= -3+4=1

hence,verified

-7,because it has been verified also:

x2-(-7)x + 12=0

x2+7x +12=0

x2+4x +3x +12=0

x(x+4)+3(x+4)=0

(x+3)(x+4)=0

now,difference= -3-(-4)= -3+4=1

hence,verified