Use the quadratic formula, x=[tex] \frac{-b+ \sqrt{ b^{2}-4ac} }{2a} [/tex]
(don't know how to type the "-"sign in the formula, so there is only the "+" in the formula)
in this case, a=1, c=34, b is unknown
from the roots, we can tell that -b+[tex] \sqrt{b^{2}-4ac } [/tex] =2(5+3i)=10+6i
Note: the original equation already give b as -b, so -(-b)=10, b=10
using b^2-4ac=(6I)^2,
b^2-4*34=-36
b^2=100
you will also get b=10
