Question

what should be sub from [3/4-2/3]to get -1/6

Answer 1

3/4-2/3=lcm of 3 and 4 =12
3/4=9/12 and 2/3=8/12
= (9/12-8/12)-x = -1/6
=1/12-x = -1/6
x = -1/6-1/12
= -2/12 - 1/12 = -1/12
answer= x = -1/12

Answer 2

3/4 - 2/3 = 9/12 - 8/12 = 1/12

 sub from 3/4 - 2/3 to get -1/6

1/12 - x = - 1/6

      -x  = -1/6 - 1/12
    -x = - 2/12 - 1/12
    -x  =  -3/12
     x  =  1/4