this is an equation of degrees 6 so it will have a total of 6 roots.If you draw the graph on calculator it touches the x axis at x = -2 and x = 2
If we plug in x =2 and x = -2 they fit the equation .
Also as the graph just touches the x axis this shows that x = 2 and x = -2 are duplicated That gives us the 4 roots and also the +/- 2i giving a total of 6 roots.
