Chapter 10 - Radical Expressions and Equations - Concept Byte - Distance and Midpoint Formulas - Page 605: 3

$d=17.6$ M$(3.5,5)$

$d=\sqrt {(x_2-x_1)^2+(y_2-y_1)^2}$ $d=\sqrt {(11-(-4))^2+(9-1)^2}$ $d=\sqrt {(15)^2+(8)^2}$ $d=\sqrt {225+84}$ $d=\sqrt {309}$ $d=17.6$ M$(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2})$ M$(\frac{-4+11}{2},\frac{1+9}{2})$ M$(\frac{7}{2},\frac{10}{2})$ M$(3.5,5)$