计算下列各题: (1) (2)25×-(-25)×+25×(-) (3) (4)(-1)2015-(1-)÷3×[2-(-3)2]
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.
(1)+(-)++(-)+(-); (2)(-0.5)+3+2.75+(-5) (3)7+(-6.9)+(-3.1)+(-8.7)