ANSWER :
A.
EXPLANATION :
Recall the quadratic formula :
[tex]x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]
From the problem :
[tex]x^2+10x+7=0[/tex]
Using the quadratic formula with a = 1, b = 10 and c = 7
[tex]\begin{gathered} x=\frac{-10\pm\sqrt{10^2-4(1)(7)}}{2(1)} \\ \\ x=\frac{-10\pm\sqrt{72}}{2} \\ \\ x=\frac{-10\pm6\sqrt{2}}{2} \\ \\ x=-5\pm3\sqrt{2} \end{gathered}[/tex]
