Answer :
[tex] x^{2} -6x-19=0 \\ \\discriminant= b^{2}-4ac=> \\ 36-(-76)=76+36=112 \\ \\ -b- \sqrt{disc.}/2a=>6- \sqrt{112}/2 \\ =>6- 4\sqrt{7}/2 \\ =3- 2\sqrt{7} \\ \\ -b +\sqrt{disc}/2a=6+4 \sqrt{7} /2 \\ =3+ 2\sqrt{7} \\ \\ Solution\: set:(3- 2\sqrt{7} ,3+ 2\sqrt{7} ) \\ \\ \framebox[1.1\width]{Good Luck!!} \par[/tex]
[tex]x^2-6x-19=0\\
x^2-6x+9-28=0\\
(x-3)^2=28\\
x-3=\sqrt{28} \vee x-3=-\sqrt{28}\\
x=3+2\sqrt7 \vee x=3-2\sqrt7[/tex]
