Subtract 1 from both sides to get 0 on the right side:



You can factor that as



Set each equal to 0:







But since you mentioned decimal approximating that
made me think you were supposed to do it using
the quadratic formula:

You would use  for ,  for ,

 for  and  for 



  

 

  

  

  x = (8±2)/2 

Using the +,

  
    
  

Using the -,

  
    
  

Edwin