Distance formula:
[tex]d = \sqrt{(x_{2}-x_1)^2 +(y_2-y_1)^2}[/tex]
Now replace the variables with the numbers (When you replace the numbers, it doesn't matter which is the first variable and second variable. Just do whatever is easiest).
[tex]d = \sqrt{(-1-(-7))^2+(5-(-1))^2}\\d = \sqrt{(-1+7)^2+(5+1)^2}\\d = \sqrt{6^2+6^2}\\d = \sqrt{36+36}\\d = \sqrt{72} \\d = 8.5[/tex]
Thus, the distance between the two points is 8.5
