72/80-(х-12/80)=15/80
116/125-(41)125-х)=94/125
4/40+у+16/40=31/49+6/40
60/90-(6/90+х)=29/90​

1) 72/80 - (x - 12/80) = 15/80

72/80 - x + 12/80 = 15/80

84/80 - x = 15/80

-x = 15/80 - 84/80

x = 69/80

2) 116/125 - (41/125 - x) = 94/125

116/125 - 41/125 + x = 94/125

75/125 + x = 94/125

x = 94/125 - 75/125 = 19/125

3) 4/40 + y + 16/40 = 31/49 + 6/40

20/40 + y = 31/49 + 6/40

y = 31/49 + 6/40 - 20/40 = 31/49 - 14/40

4) 60/90 - 6/90 - x = 29/90

54/90 - x = 29/90

-x = -25/90 = 25/90 = 5/18

1)72/80-(x - 12/80) = 15/80

60/80 - x = 15/80

x = 60/80 - 15/80

x = 45/80

x = 9/16

2)116/125-(41)125-х)=94/125

41/125-x=116/125-94/125

41/125-x=22/125

x=41/125-22/125

x=19/125

3)4/40+у+16/40=31/49+6/40

1/2+y=31/49*3/20

1/2+y=93/980

y=93/980-1/2

y=-397/980

4)60/90-(6/90+х)=29/90​

6/90+x=60/90-29/90

6/90+x=31/90

x=31/90-6/90

x=25/90