67-21y=25 83+29x=982
(63-y)+109=121
103-(z+47)=54
122+(y-7)=200
53-(y-13)=24
это уравнения
до конца урока 30 мин

67-21y=25

21y=67-25

21y=42

y=42:21

y=2

83+29x=982

29x=982-83

29x=899

x=899:29

x=31

(63-y)+109=121

63-y=121-109

63-y=12

y=63-12

y=51

103-(z+47)=54

z+47=103-54

z+47=49

z=49-47

z=2

122+(y-7)=200

y-7=200-122

y-7=78

y=78+7

y=85

53-(y-13)=24

y-13=53- 24

y-13=29

y=29+13

y=42