tatsach

1)=-5/12-(-5/9-(-3/8))=-5/12+5/9-3/8=

-30/72+40/72-27/72=17/72

2)=-5 7/16-(3 5/8-(-8 3/10))=-5 7/16-3 5/8

-8 3/10=-5 35/80-3 50/50-8 24/80=

-16 109/80=-17 29/80