Answer:
[tex]x(x {}^{2} - 8x - 20) = 0[/tex]
Use the quadratic formula to simply the second degree equation;
[tex]x(x + 2)(x - 10)[/tex]
[tex]x1 = 0[/tex]
[tex]x2 = - 2[/tex]
[tex]x3 = 10[/tex]