The given points are,
[tex]\begin{gathered} (x_1,y_1)=\mleft(-7,4\mright) \\ (x_2,y_2)=\mleft(5,8\mright) \end{gathered}[/tex]The distnace between the two point formula is,
[tex]D=\sqrt[]{(x_2-x_1)^2+(y_2-y_1)}^2[/tex]subsitute the points in the formula,
[tex]\begin{gathered} D=\sqrt[]{(5-(-7))^2+(8-4)^2} \\ =\sqrt[]{(5+7)+(8-4)^2} \\ =\sqrt[]{(12)^2+(4)^2} \\ =\sqrt[]{144+16} \\ =\sqrt[]{160} \\ =\sqrt[]{16\times10} \\ =\sqrt[]{4\times4\times10} \\ =4\sqrt[]{10} \\ =4\times3.162 \\ =12.64 \\ \end{gathered}[/tex]the answer is 12.6.ok