

Sum of -13/5 and 12/7 = (-13/5) + (12/7)
= (-13*7 + 12*5)/(7*5)
= (-91+60)/35
= -31/35
Product of -13/7 and -1/2 = (-13/7) * (-1/2)
= (13*1)/(7*2)
= 13/14
Now division -31/35 and 13/14 = (-31/35)/(13/14)
= (-31*14)/(35*13)
= (-31*2)/(5*13) (35 and 14 is divided by 7)
= -61/65
