[tex]\bf \textit{distance between 2 points}\\ \quad \\
\begin{array}{lllll}
&x_1&y_1&x_2&y_2\\
% (a,b)
&({{ -5}}\quad ,&{{ 5}})\quad
% (c,d)
&({{ 2}}\quad ,&{{ 6}})
\end{array}\qquad
% distance value
d = \sqrt{({{ x_2}}-{{ x_1}})^2 + ({{ y_2}}-{{ y_1}})^2}
\\\\\\
d=\sqrt{[2-(-5)]^2+[6-5]^2}\implies d=\sqrt{(2+5)^2+(6-5)^2}
\\\\\\
d=\sqrt{7^2+1^2}\implies d=\sqrt{50}[/tex]