Respuesta :

phinnae003
so first you are gonna add +6 on both sides 
  -2/3a-6=12
now you will get -2/3a=18
then you are gonna multiply -2/3 on both sides leaving the "a" alone
(-2/3)-2/3a=18(-2/3)
now you will get a=-12 and that will be your answer.