Solve the inquality algebraically

Solution:


intervals of interest: 
(-oo,-2) , (-2, 2), (2,4), and (4, oo), why? 

Testing... 
if x=-3 then -7/5 is less than 0 
if x=0 then -4/-4 is not less than 0 
if x=3 then -1/5 is less than 0 
if x=5 then 1/21 is not less than 0 
so the solutions is 
(-oo,-2) U (2,4)