 
David W. answered  03/07/16
Tutor
                    
        4.7
        (90)
            Experienced Prof
Read and re-read the problem until you understand it and can put it into your own words. How’s this: Starting with x, 10% increase, then 5% decrease is $209.
Let x = price Sam paid
Translate:
   "Sam sold his car to David at a profit of 10%"     
          means Sam sold car for 1.10x
  "David sold the car to Rita for $209 at a loss of 5%"    means
                                             $209 = 0.95(1.10x)
   $209 = 0.95(1.10x)             [re-write]
     $200 = x
Checking (very important):
Sam sold his $200 car to David at a profit of 10% ($220).  David sold the car to Rita for $209, which is a loss of $11 or $11/$220 or 5%).     Check!
 
     
             
                     
                    