Please help me get the answer

You need to isolate a.
First subtract 1 from both sides:
-3a > 27
Then divide both sides by -3. Since you are dividing by a negative number the sign > should change to <.
The answer is a < -9
(There should be a line under the sign <.)
Answer:
Step-by-step explanation:
[tex]-3a+1\geq28\qquad\text{subtract 1 from both sides}\\\\-3a+1-1\geq28-1\\\\-3a\geq27\qquad\text{change the signs}\\\\3a\leq-27\qquad\text{divide both sides by 3}\\\\a\leq-9[/tex]