Answer:

Step-by-step explanation:
1) Move all terms to one side.

2) Factor  using Polynomial Division.
 using Polynomial Division.
1 -  Factor the following.

2 -  First, find all factors of the constant term 210.

3) Try each factor above using the Remainder Theorem.
Substitute 1 into x. Since the result is not 0, x-1 is not a factor..

Substitute -1 into x. Since the result is not 0, x+1 is not a factor..

Substitute 2 into x. Since the result is not 0, x-2 is not a factor..

Substitute -2 into x. Since the result is not 0, x+2 is not a factor..

Substitute 3 into x. Since the result is not 0, x-3 is not a factor..

Substitute -3 into x. Since the result is not 0, x+3 is not a factor..

Substitute 5 into x. Since the result is 0, x-5 is a factor..

------------------------------------------------------------------------------------------
⇒ 
4)  Polynomial Division: Divide  by
  by  .
.
                                                 
                        
                      
                                       -------------------------------------------------------------------------
 |
                               |     
                           
                      
     
                                             
                              
 
                                         -----------------------------------------------------------------------
                                                                               
                 
       
                                      --------------------------------------------------------------------------
                                                                            
                              
                                                                           
                               
                                       -------------------------------------------------------------------------
5)  Rewrite the expression using the above.


3) Solve for 

4)  Use the Quadratic Formula.
1 - In general, given  , there exists two solutions where:
 , there exists two solutions where:

2 -  In this case,  and
 and 

3 - Simplify.

5) Collect all solutions from the previous steps.
