79/80-(3/16+39/80)=
2/45+(41/45-7/9)=
7/15-(2/15+1/5)=
3/16+(15/16-5/8)=​

Пошаговое объяснение:

79/80-(3/16+39/80)=5/16

3/16+39/80=(3*5+39)/80=54/80

79/80-54/80=(79-54)/80=25/80=5/16

2/45+(41/45-7/9)=8/45

41/45-7/9=(41-7*5)/45=6/45

2/45+6/45=(2+6)/45=8/45

7/15 -(2/15+1/5)= 2/15 (здесь символ пропущен?! я поставила -)

2/15+1/5=(2+1*3)/15=5/15

7/15-5/15=(7-5)/15=2/15

3/16+(15/16-5/8)=

15/16-5/8=(15-2*5)/16=5/16

3/16+5/16=(3+5)/16=8/16=1/2