пожалуйста, помогите как можно быстрее!!! дам 15 баллов!

А) 4 1/9*3=37/9*3=37/3=12 1/3
Б) (1 1/2+2/3)*6=(1 3/6+4/6)*6=
=(1 7/6)*6=13/6*6=13

А) 3/7z-5/14z+5/28z=
=12/28z-10/28z+5/28z=7/28z=1/4z
Б) 5 3/8b-2 1/3b-1/24b=
=5 9/24b-2 8/24b-1/24b=3 1/24b-1/24b=3b

4 1/4m-(1 7/12m+3/8m)=
=4 1/4m-(1 14/24m+9/24m)=
=4 1/4m-1 23/24m=
=4 6/24m-1 23/24m=
=3 30/24m-1 23/24m=
=2 7/24m
При m=48,
2 7/24m=2 7/24*48=
=55/24*48=110

(2/5x-2 2/3)*15=2
2/5x-2 2/3=2/15
2/5x=2/15+2 2/3
2/5x=2/15+2 10/15
2/5x=2 12/15
x=2 12/15:2/5
x=42/15:2/5
x=42/15*5/2
x=21/3
x=7