а)-1/3-0,5=-1/3-5/10=-10/30-15/30=-25/30=-5/6

б)-2/7+0,3=-2/7+3/10=-20/70+21/70=1/70

в)-2/9+1,2=-2/9+1 2/10=-2/9+12/10=-20/90+108/90=88/90=44/45

г)0,72:(-48/49)=72/100:(-48/49)=72/100*(-49/48)=6/100*(-49)/4=-294/400=-147/200=-735/1000=-0,735

a) – 1/3 – 0,5

– 1/3 – 1/2

– 5/6

б) – 2/7 + 0,3

– 2/7 + 3/10

1/70

в) – 2/9 + 1,2

– 2/9 + 6/5

44/45

г) 0,72 ÷ (– 48/49)

18/25 ÷ (– 48/49)

– 18/25 ÷ 48/49

– 18/25 × 49/48

– 3/25 × 49/8

– 147/200