2、ax-3 & gt； 0, when a>0, x & gt3/a, because: x≤ 1, that is, 3/a.

3. When a>0, ax>3, x & gt3/a, because A.

4. 4x-6(x+ 1)>X <-1, | 3x+1| |1-3x | is simplified to-(3x+1)+(/kloc-0)