Review: 4x-5<11 (you just solve to find x) so 4x<16 => x<4. If diving by negative you must switch sign.

You do the exact same solving for quadratics.

Factor=   then zero product so x=4 then you test a number greater and smaller then 4 in the original equation to see what the restriction is and if the solution is true.

Try 0 (if you can)

=> 16>0 which is true

Try greater number: 5 in this case

=> 1>0 which is also true

 

So the solution/restrictions are x<4 and x>4 to make this quadratic equation true.