Bom Dia !!!

b) 12 + 5 (9 + y) = 6 (11 - y)

b) 12 + 45 + 5y = 66 - 6y

b) 5y + 6y = 66 - 57

b) 11y = 9

b) y = 11 / 9

ou

b) y ≅ 1,222...

c) 5x - 4 = 6x + 8

c) 5x - 6x = 8 + 4

c) - x = 12  . ( - 1 )

c) x = -12

d) w - 5 = -2w + 22

d) w + 2w = 22 + 5

d) 3w = 27

d) w = 27 / 3

d) w = 9

Espero ter ajudado :-)

Att: LDC