计算:(每小题3分,共12分)(1)-4-5+7 (2)8×(-1)2-(-4)+(-3) (3)(-2)3÷-(-5)× (4)5(x-3 y) - (-2 y+x )
计算:
(本小题满分6分)计算:-(3.14-)0+(1-cos30°)×()-2
计算:.(本小题6分)