a. $\sqrt{(3+2.\sqrt{3})^{2}} - \sqrt{(3-2.\sqrt{3})^{2}} =\vert 3+2.\sqrt{3} \vert + \vert 3-2.\sqrt{3} \vert=3+2.\sqrt{3} +2.\sqrt{3}-3 =4.\sqrt{3}$
do $2.\sqrt{3} > 3$
b.$4.\sqrt{3}+ \sqrt{(\sqrt{3}-2)^{2}} = 4.\sqrt{3} + \vert \sqrt{3} -2 \vert =4.\sqrt{3}+2-\sqrt{3}=3.\sqrt{3}+2 $
do $\sqrt{3}<2$