Respuesta :

Attached is the working out. 

In short, i) is the most suitable answer but refer to the attachment for more. :) 

Ver imagen tinmann
We may use the quadratic formula to answer the question above, 
                                        x = (-b +/- sqrt (b² - 4ac)) / 2a
From the equation, a = 2, b = 1, c = 10. Substituting the known values,
                                  x = (-1 + sqrt (1² - 4(2)(10)) / 2(2)
                                  x = (-1 + sqrt (1² - 4(2)(10)) / 2(2)
The radicands of both the equations are negative. Therefore, the roots are not real.