如图,Rt△ABC中,∠C=90°,AD平分∠CAB,DE⊥AB于E,若AC=6,BC=8,CD=3.(1)求DE的长;(2)求△ADB的面积.
m2+2n-mn-2m
(a2+1)2-4a2
5m(x-y)2+10n(y-x)3
-8ax2+16axy-8ay2
(a+b)2-9(a-b)2