Math équations : besoin d'aide svp​

Bonsoir,

a)

5x= 8+7

5x = 15

x= 15/5

x = 3

b)

-2-18 = 10y

-20 = 10y

y = -20/10

y = -2

c)

9y = -29 -7

9y = -36

y = -36/9

y = -4

d)

3x-3 =3

3x = 3+3

3x = 6

x= 6/3

x= 2

e)

12 -3/2 = 6x

24/2 -3/2 = 6x

21/2 = 6x

6x = 21/2

x = (21*6) /2

x= 63

f)

5x/3 -2x/3 = -1/5 -1/5

3x/3 = -2/5

x = -2/5