A=-3 is obtained by solving the upper countable equation 2=-(a- 1).

2.x > can be obtained by simplification; -1.5a-2.5 and the solution is x >；; The solution of-1 is-1.5a-2.5=- 1, and a=- 1.

3. x≤0.5m, 3 ≤ X < 4, ∴ 6 ≤ M <; eight

That's the whole process. Thank you for coming.