Let that value is x

1. Now if the question is

      what is (-8/2) *3 = 2/4 

then

      x* (-8/2) *3 = 2/4

=> x*(-4*3) = 1/2

=> -12x = 1/2

=> x = 1/(-12*2)

=> x = -1/24

So that number is -1/24

2. If the question is

        what is -8/(2*3) = 2/4 

then

      x* {-8/(2*3)} = 2/4

=> x*(-4/3) = 1/2

=> x = (1/2)/(-4/3)

=> x = -(1*3)/(2*4)

=> x = - 3/8

So that number is -3/8