[tex]The\ distance\ between\ A(x_A;\ y_A)\ and\ B(x_B;\ y_B):\\\\d=\sqrt{(x_B-x_A)^2+(y_B-y_A)^2}\\\\------------------------------\\\\A(12;-1);\ B(0;-6)\\\\subtitute\\\\d=\sqrt{(0-12)^2+(-6-(-1))^2}=\sqrt{(-12)^2+(-5)^2}\\\\=\sqrt{144+25}=\sqrt{169}=\boxed{13} [/tex]
