[tex]A(2, -3),\ B(1,\, 4)\\\\\overrightarrow{AB}=\big[1-2,\ 4-(-3)\big]=\big[{-}1,\, 7\big]\\\\|\overrightarrow{AB}|=\sqrt{({-}1)^2+7^2}=\sqrt{1+49}=\sqrt{50}=5\sqrt2[/tex]
[tex]A(0, -6),\ B(11,\, 0)\\\\\overrightarrow{AB}=\big[11-0,\ 0-(-6)\big]=\big[11,\, 6\big]\\\\|\overrightarrow{AB}|=\sqrt{11^2+6^2}=\sqrt{121+36}=\sqrt{157}[/tex]
[tex]A(-4, -8),\ B(1{,}5\,;\,9)\\\\\overrightarrow{AB}=\big[1{,}5-(-4),\ 9-(-8)\big]=\big[5{,}5\,;\, 17\big]\\\\|\overrightarrow{AB}|=\sqrt{(5{,}5)^2+17^2}=\sqrt{30{,}25+289}=\sqrt{319{,}25}=\sqrt{\frac{1277}4}=0{,}5\sqrt{1277}[/tex]
