Chapter 7 - Review - Page 469: 80

$\sqrt{275.6} \text{ units OR }\approx 16.601 \text{ units}$

Using the Distance Formula, $d=\sqrt{(x_1-x_2)^2+(y_1-y_2)^2}$, the distance between the given points is \begin{array}{l} \sqrt{(7.4-(-1.2))^2+(-8.6-5.6)^2} \\\\= \sqrt{73.96+201.64} \\\\= \sqrt{275.6} \text{ units OR }\approx 16.601 \text{ units} .\end{array}