Verified answer

16x^3 + 8x^2 + x = 0

x(16x^2+8x+1)=0

x=0   i    16x^2+8x+1-0

                D=b^2-4ac = 8^2-4*16*1 = 64-64=0

                D=0 - одно решение

                                                                                            -b

при дискриминанте равным нулю формула D =----------

                                                                                             2a

x=-8/2*16 = -8/32 = -1/4

OTBET: x=-1/4 i x=0

вроде так