9.下列各组数中,互为相反数的是( )
| A. | 5和-$\frac{1}{5}$ | B. | 2与-2 | C. | -1与-1 | D. | 0.01与|-0.01| |
8.“a与b的$\frac{1}{10}$的差”,用代数式表示为( )
| A. | $\frac{1}{10}$(a-b) | B. | a-$\frac{1}{10}$b | C. | a+b-$\frac{1}{10}$ | D. | a-b-$\frac{1}{10}$ |
7.已知A=3m2-7m+5,B=-3m2-7m-7,则B-A一定( )
| A. | 大于0 | B. | 等于-12或-6 | C. | 小于0 | D. | 最大值为12 |
20.(-$\frac{1}{4}$)2006×(-4)2007的结果是( )
0 309619 309627 309633 309637 309643 309645 309649 309655 309657 309663 309669 309673 309675 309679 309685 309687 309693 309697 309699 309703 309705 309709 309711 309713 309714 309715 309717 309718 309719 309721 309723 309727 309729 309733 309735 309739 309745 309747 309753 309757 309759 309763 309769 309775 309777 309783 309787 309789 309795 309799 309805 309813 366461
| A. | -1 | B. | 1 | C. | -$\frac{1}{4}$ | D. | -4 |