For what value of k the zeros of the polynomial x square 5 x K are differ by one that is alpha minus beta is equal to 1?

Verify that the numbers given alongside of the cubic polynomials below are their zeroes. Also, verify the relationship between the zeroes and coefficients in each case:
2x3 + x2 –5x + 2; 1/2, 1,–2 

Let p(x) = 2x3+x2–5x + 2 Comparing the given polynomial with ax3 + bx3 

+ cx + d, we get
                    

Now, 
                     
                           

                          

          
                    
and   
                  
∴    are the zeroes of 
Hence, verified.Here, we have

Now,    
         
                            
and           
                                   Hence verified.