Question 411026
a=-1, b=6, c=-21
x=(-6+-sqrt(36-4*21))/-2 not /2 and not -4(1)(-21) should be -4(-1)(-21)
=(-6+-sqrt(-48))/-2
=(-6+-4sqrt(3)i)/-2
=3+-2sqrt(3)i
=3+2sqrt(3)i, =3-2sqrt(3)i
.
Ed