Answer:
[tex]x=-3(+/-)3\sqrt{2}[/tex]
Step-by-step explanation:
we know that
The formula to solve a quadratic equation of the form
[tex]ax^{2} +bx+c=0[/tex]
is equal to
[tex]x=\frac{-b(+/-)\sqrt{b^{2}-4ac}} {2a}[/tex]
in this problem we have
[tex]x^{2} +6x-9=0[/tex]
so
[tex]a=1\\b=6\\c=-9[/tex]
substitute in the formula
[tex]x=\frac{-6(+/-)\sqrt{6^{2}-4(1)(-9)}} {2(1)}[/tex]
[tex]x=\frac{-6(+/-)\sqrt{72}} {2}[/tex]
[tex]x=\frac{-6(+/-)6\sqrt{2}} {2}[/tex]
[tex]x=-3(+/-)3\sqrt{2}[/tex]
