Adding a negative fraction #B# to another fraction #A# means subtracting the number part of it (that means leaving the minus sign) to #A#
For example if we have to add #5/6# and #-1/3#, this means, subtracting #1/3# from #5/6# or #5/6-1/3#. The latter is equal to #5/6-2/6=(5-2)/6=3/6=(1cancel3)/(2cancel6)=1/2#
Hence #5/6+(-1/3)=1/2#.
Subtracting a negative fraction #B# from another fraction #A# means adding the number part of it (that means leaving the minus sign) to #A#.
For example if we have to subtract #-3/8# from #-1/4# means, adding #3/8# to #-1/4# or #-1/4+3/8# and as #-1/4# equal to #-2/8#, #-1/4+3/8=-2/8+3/8=(-2+3)/8=1/8#
Hence #-1/4-(-3/8)=-1/4+3/8=1/8#.
