Answer:24
Step-by-step explanation: If she bought x amount of posters and had 12 left after, you'd multiply 12 by 2 and get 24. Half of 24 is 12. So Micaela bought 24 posters.
Answer: 42
explanation : 90-48=41
Solution
-6x - 3y = 9 Add 6x to both sides
-6x + 6x - 3y = 9 + 6x
-3y = 9 + 6x Or more conventionally
-3y = 6x + 9 Divide by - 3
y = 6x/-3 + 9/-3
y = - 2x - 3
