\[ \vec{AB} = \sqrt{(x_B - x_A)^2 + (y_B - y_A)^2 + (z_B - z_A)^2} \]
\[ \vec{AB} = \sqrt{(-2 - 10)^2 + (2 - 5)^2 + (-1 - 3)^2} \]
\[ \vec{AB} = \sqrt{(-12)^2 + (-3)^2 + (-4)^2} \]
\[ \vec{AB} = \sqrt{144 + 9 + 16} \]
\[ \vec{AB} = \sqrt{169} \]
\[ \vec{AB} = 13 \]
Ответ: 13