Respuesta :

Answer:

multiple 6 with numbers inside paranthesis:

12x - 66 + 15 = 21

add 66 fhen substrack 15 from both sides :

12x = 72 divide both sides with 12:

x = 6

Step-by-step explanation:

dddiamond

In his answer above he didn’t add 81 to both sides. (Somebody correct me if I’m wrong)

Ver imagen dddiamond