2x^2+8x=-26
divide both sides by 2
x^2+4x=-13
add 13 both sides
x^2+4x+13=0
a=1
b=4
c=13
x=[tex] \frac{-4+/- \sqrt{4^2-4(1)(13)} }{2(1)} [/tex]
x=[tex] \frac{-4+/- \sqrt{16-52} }{2} [/tex]
x=[tex] \frac{-4+/- \sqrt{-36} }{2} [/tex]
x=[tex] \frac{-4+/- (\sqrt{-1})(\sqrt{36}) }{2} [/tex]
x=[tex] \frac{-4+/- i\sqrt{36} }{2} [/tex]
x=[tex] \frac{-4+/- 6i}{2} [/tex]
x=-2+/-3i
solutions are
-2+3i and -2-3i
