\(\frac{x^2+10x-7}{x^2+10x+25} =0\\x^2+10x-7=0\\x= \frac{-b\pm\sqrt{b^2-4ac}}{2a}\);
where a = 1, b = 10 and c = -7
\(x=\frac{-10\pm\sqrt{10^2-(4\times1\times(-7)}}{2\times1}\\=\frac{-10\pm\sqrt{100+28}}{2}=\frac{-10\pm\sqrt{128}}{2}\\=\frac{-10\pm\sqrt{64\times2}}{2}=\frac{-10\pm8\sqrt{2}}{2}=-5\pm4\sqrt{2}\\=-5+4\sqrt{2} \ or \ -5-4\sqrt{2}\\x=0.66 \ or \ x = -10.66\)
