计算:
(1) | - 2 3 | - 12 + ( 1 3 ) - 2 ;
(2) ( x - 2 ) 2 - ( x + 2 ) ( x - 2 ) .
计算:sin30°·cos60°-cos30°·tan60°
计算:.
计算:(1)+-2012+();(2)(1-)—