1.15(у+2)=2(у+5)
2.1,5у-0,5у=8(у-1)
3.7х-3(х+1)=18
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Пошаговое объяснение:

1.

15(у+2)=2(у+5)

15y + 30 = 2y + 10

15y - 2y = 10 - 30

13y = -20

y = -20:13

y = -1 7/13

2.

1,5у-0,5у=8(у-1)

y = 8y - 8

8y - y = 8

7y = 8

y = 8:7

y = 1 1/7

3.

7х-3(х+1)=18

7x - 3x - 3 = 18

4x - 3 = 18

4x = 18+3

4x = 21

x = 21:4

x = 5,25