Номер 73 Помогите очень надобно все по деяниям

9/10-4/15+2/5=1.1/30
9/10-4/15=27/30-8/30=19/30
19/30+2/5=19/30+12/30=31/30=1.1/30

5/6-(7/18+2/15)=14/45
7/18+2/15=35/90+12/90=47/90
5/6-47/90=75/90-47/90=28/90=14/45

9/10-4/15+2/5=1 1/30
1) 9/10  -  4/15 =   (9 3  -  4 2)/30 = 27/30  -  8/30 =  19/30
2)19/30  +  2/5 =(19 1  +  2 6)/30 = 19/30  +  12/30 =  31/30 = 1 1/30

5/6-(7/18+2/150=14/45
1)7/18 + 2/15 = (7 5  +  2 6)/90 = 35/90  +  12/90 =  47/90
2)5/6 -  47/90 = (5 15  -  47 1)/90 = 75/90  -  47/90 =  28/90 = 14/45