如图,CA=CD,∠B=∠E,∠BCE=∠ACD.求证:AB=DE.
-2+5
计算:(1).(2)5.6+(-0.9)+4.4+(-8.1)(3)(4).(5) (6)
(本题6分)+()-1-sin45°+|-2013|
(本题6分)计算:
计算下式的值:211×555+445×789+555×789+211×445.