11．脱式计算，能简算的要简算．
0 158784 158792 158798 158802 158808 158810 158814 158820 158822 158828 158834 158838 158840 158844 158850 158852 158858 158862 158864 158868 158870 158874 158876 158878 158879 158880 158882 158883 158884 158886 158888 158892 158894 158898 158900 158904 158910 158912 158918 158922 158924 158928 158934 158940 158942 158948 158952 158954 158960 158964 158970 158978 199269
| 2.55÷1.7-0.59 | 3.7×7.9+3.7×2.1 | （2-0.4）÷$\frac{8}{15}$ |
| $\frac{8}{9}$÷0.625÷$\frac{5}{4}$ | $\frac{3}{7}$×（$\frac{4}{5}$-$\frac{2}{3}$）÷$\frac{5}{14}$ | $\frac{3}{4}$×93+6×0.75+75% |