Answer:
-3/8= -6/16=-9/24=-12/32=-15/40....
3/8=6/16=9/24=12/32=15/40=18/48=21/56.....
The least common multiple between 3 and 4 is 12, so we can use this fact to rewrite both 1/3 and 1/4 in 12ths:

We're left with an answer of
7/12, which can't be reduced.
Hope this helps! sorry if it is kind of dark