1.计算:(1)_________; (2)_____________.
2.计算:(1) ___________; (2)______________.
3.计算:(1) ________; (2) ____________.
4.计算:____________.
5.计算:(1) __________; (2)__________.
6.(1)若,则m=_________; (2)若,则m=_________.
7.一长方体的长、宽、高分别是cm、cm、cm,则它的体积是_________.
8.下列运算正确的是 ( )