Question

divide the difference of -2/5 and -4/15 by their sum

Answer 1

-2/5-(-4/15)  =  -2/5 + 4/15
                    =   -6+4/15
                     =  -2/15
-2/5+(-4/15) = -6-4/15 
                    = -10/15
                     = -2/3
Dividing the difference of -2/5 and -4/15 by their sum we get 
                                           =  -2/15/ -10/15
                                            =  1/5