1) -5/12-(-5/9-(-3/8))= -5/12-(-5/9)-3/8=-5/12+5/9-3/8=5/9-5/12-3/8=60/108-45/108-3/8=15/108-3/8=5/36-3/8=10/72-27/72=-17/72
2)-5 7/16-(3 5/8-(-8 3/10))=-5 7/16 - 3 5/8 - 8 3/10=-5 7/16 - 3 10/16 - 8 3/10=-9 1/16 +(-8 3/10)=-9 5/80 +(-8 24/80)=-17 29/80