mathematics - Make the equation true by only drawing a single straight line

Fred has a puzzle. The instruction sheet, which is separate from the equation,simply says: "Make this equation true. You may ONLY draw ONE, PERFECTLY straight line". The equation is all alone on a blank piece of paper and reads:

5+5+5=550

There are 4 acceptable answers. You must get all 4 for a correct answer.

Answer

1. 
   

   
   

   Cross out the equals sign

   
   

   
   


2. 
   

   
   

   Turn the first $+$ into a 4 giving $545+5=550$

   
   

   
   



3. 
   

   
   

   Turn the second $+$ into a 4 giving $5+545=550$

   
   

   
   


4. 
   

   
   

   Turn the equals sign into less than or equal to