9.北京到上海的距离约是1050千米,画在比例尺是1:3000000的地图上,应画35厘米.
a与b成反比例时,a与b成正比例时,“?”是1.6;“?”是10.
| a | 4 | ? |
| b | 100 | 250 |
7.计算下面各题(能简算的要用简便方法算)
0 157721 157729 157735 157739 157745 157747 157751 157757 157759 157765 157771 157775 157777 157781 157787 157789 157795 157799 157801 157805 157807 157811 157813 157815 157816 157817 157819 157820 157821 157823 157825 157829 157831 157835 157837 157841 157847 157849 157855 157859 157861 157865 157871 157877 157879 157885 157889 157891 157897 157901 157907 157915 199269
| 60×($\frac{2}{5}$+$\frac{3}{4}$-$\frac{1}{2}$) | ($\frac{24}{19}$+$\frac{16}{17}$)×$\frac{1}{8}$+$\frac{15}{17}$ | $\frac{2}{3}$÷$\frac{5}{9}$-$\frac{3}{8}$×$\frac{4}{5}$ |
| $\frac{5}{8}$×$\frac{11}{10}$+$\frac{3}{8}$÷$\frac{10}{11}$ | $\frac{5}{6}$÷[$\frac{6}{7}$×($\frac{2}{9}$+$\frac{1}{6}$)] | $\frac{5}{9}$÷[$\frac{4}{5}$×($\frac{3}{8}$+$\frac{1}{4}$)] |