计算: ( - 1 ) 3 + 1 - 1 2 ∣ - ( - 3 2 ) 0 × ( - 2 3 ) .
如图,点B、F、C、E在同一直线上,∠A=∠D,BF=CE,AC∥DF. 求证:△ABC≌△DEF.
计算:.
计算: