Résoudre les équations suivantes : a) 4x + 7 = x - 9 b) 12 - 3x = 6x + 9 c) 2 (x - 3) = 16 d) 4 - 5y = 8y - 2 help me pleaaaase !!!

a) 4x + 7 = x - 9
4x-x = -9 -7
3x = -16
x =  -16/3


b) 12 - 3x = 6x + 9

-3x -6x = 9 -12
-9x = 3
x =  -3/9
x =  -1/3

c) 2 (x - 3) = 16
2x -6 =16
2x = 16 +6
2x = 22
x =22/2
x = 11

d) 4 - 5y = 8y - 2
-5y -8y  =  -2 -4
-13 y = -6
y =  -6/ -13
y = 6/13