Chapter 2 - Functions and Graphs - Exercise Set 2.8 - Page 319: 16

$d = 11.09$

$d = \sqrt {(2\sqrt {3} - (-\sqrt {3}))^{2}+(\sqrt {6} -5\sqrt {6})^2}$ $=\sqrt {(2\sqrt {3} +\sqrt {3}))^{2}+(-4\sqrt {6})^2}$ $= \sqrt {(3\sqrt {3} )^{2}+(-4\sqrt {6})^2}$ $= \sqrt {(9 \times 3) + (16 \times 6)}$ $= \sqrt {27 + 96}$ $= \sqrt {123}$ $= 11.0905...$ $= 11.09$