Respuesta :

Answer:

a = (-7)

Step-by-step explanation:

Firstly clear the bracket...,

-6(-2 + a) = 12 - 6a

Then substitute the simplified version in place of bracket...,

; 12 - 6a = 54

; -6a = 54 - 12

; -6a = 42...then divide both sides by (-6)

Therefore...., a = (-7)