Решите уравнения: а) 15 / (7-y) = 5 б) 42/y = 3 в) (12+y) / 9 = 3 г) (14+х) / 9 = 5 д) y - 13/27 = 10/27 е) 4 1/5 + x = 7 4/5 ж) (8/15 + x) - 7/15 = 11/15 з) x/42 - 5/42 = 35/42

(Это дроби)

А)

15 / (7-y) = 5

7-y=15:5

7-y=3

y=7-3

y=4

б)

42/y = 3

y=42:3

y=14

в)

(12+y) / 9 = 3

12+y=3*9

12+y=27

y=27-12

y=15

г)

(14+х) / 9 = 5

14+y=5*9

14+y=45

y=45-14

y=31

д)

y - 13/27 = 10/27

y = 10/27 + 13/27

y = 23/27

е)

4 1/5 + x = 7 4/5

x = 7 4/5 - 4 1/5

x = 3 3/5

ж)

(8/15 + x) - 7/15 = 11/15

8/15 + x - 7/15 = 11/15

1/15 + x = 11/15

x = 11/15 - 1/15

x = 10/15

x = 2/3

з)

x/42 - 5/42 = 35/42

x/42 = 35/42 + 5/42

x/42 = 40/42

x = 40/42 * 42

x = 40