+9665 \(x^2=169\\ x^2 + 0 x - 169 = 0\\ x = \dfrac{-0\pm\sqrt{0^2-4(1)(-169)}}{2(1)}\\ \;\;=\dfrac{\pm 26}{2}\\ \;\;=13 \text{ OR }-13\)
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Well, what you'e trying to do is isolate x.
The best way to do it in this case is to find the square root of both sides in order to isolate x.
But, you must make sure that the right side has plus or minus, since both plus and minus square root of 169 = 169
So:
\(x^2 = 169\)
\(\sqrt{x^2} = \pm \sqrt{169} \)
\(x = \pm 13 \)
x = 13 or x = -13
