Micaela bought for posters. A week later half of all her posters were lost during a move. There are now only 12 posters left. How many did she start with?

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.

24

Step-by-step explanation:

12 is half of what is left.

12+12=24

a4 - 3a2 - 1

step-by-step explanation:

step   1   :

equation at the end of step   1   :

  ((a4) -   3a2) -   1

step   2   :

trying to factor by splitting the middle term

2.1     factoring   a4-3a2-1  

the first term is,   a4   its coefficient is   1 .

the middle term is,   -3a2   its coefficient is   -3 .

the last term, "the constant", is   -1  

c

step-by-step explanation: