For this case we have the following expression:
[tex]-1.5x-3.1 <5.5[/tex]
Adding 3.1 to both sides of the inequality:
[tex]-1.5x <5.5 + 3.1\\-1.5x <8.6[/tex]
Dividing between -1.5 on both sides of the inequality, keeping in mind that the sign changes direction:
[tex]x> \frac {8.6} {- 1.5}\\x> -5.73333[/tex]
Answer:
[tex]x> -5.73333[/tex]