13.表示X和Y成反比例的关系式是( )
A. | X+Y=1 | B. | X-Y=1 | C. | XY=1 |
12.一种商品打七折,原价要80元,现在可以少用( )元.
0 159696 159704 159710 159714 159720 159722 159726 159732 159734 159740 159746 159750 159752 159756 159762 159764 159770 159774 159776 159780 159782 159786 159788 159790 159791 159792 159794 159795 159796 159798 159800 159804 159806 159810 159812 159816 159822 159824 159830 159834 159836 159840 159846 159852 159854 159860 159864 159866 159872 159876 159882 159890 199269
A. | 30 | B. | 24 | C. | 35 | D. | 56 |