The symbol "£" mean "pound" (money) in some countries such as England.
But I think the symbol you're talking about is ≤ which means less than 
or equal to. 

|4x+3| ≤ 5    

To solve that we write the |4x+3| as ±(4x+3)

±(4x+3) ≤ 5

and write as two separate inequalities one with + and one with -

+(4x+3) ≤ 5            -(4x+3) ≤ 5
   4x+3 ≤ 5              -4x-3 ≤ 5
     4x ≤ 2                -4x ≤ 5
      x ≤ 2/4                x ≥ -4/5
      x ≤ 1/2

Rewrite  x ≥ -4/5 as -4/5 ≤ x  and write  ≤ 1/2 on the right:

Answer:

  -4/5 ≤ x  ≤ 1/2
  
----------------------------

-3 < 2x-3 ≤ 11      Add 3 to all three sides to solve for x in the middle:
+3     +3   +3 
--------------
 0 < 2x   ≤ 13

Divide all three sides by 2

 0 < x ≤ 13/2

Edwin