Answer :

AL2006

1).  You have 12 of something, and 1 of the same thing is taken away.
How many of it do you have then ?

2).  You have 3 of something, and 6 more come along.
How many of it do you have then ?

3).  Simplified.


1. 12-1 = 11   11a
2. 3+6 = 9  9x
3. 3x-1 (already simplified - not 'like' terms)