9.在Rt△ABC中,∠C=90°,AB=5,BC=3,则AC为( )
| A. | 4 | B. | 16 | C. | $\sqrt{34}$ | D. | 8 |
20.为执行“两免一补”政策,某地区2006年投入教育经费2500万元,预计2008年投入3600万元,设这两年投入教育经费的年平均增长百分率为x,则下列方程正确的是( )
0 293856 293864 293870 293874 293880 293882 293886 293892 293894 293900 293906 293910 293912 293916 293922 293924 293930 293934 293936 293940 293942 293946 293948 293950 293951 293952 293954 293955 293956 293958 293960 293964 293966 293970 293972 293976 293982 293984 293990 293994 293996 294000 294006 294012 294014 294020 294024 294026 294032 294036 294042 294050 366461
| A. | 2500(1+x)+2500(1+x)2=3600 | B. | 2500(1+x%)2=3600 | ||
| C. | 2500x2=3600 | D. | 2500(1+x)2=3600 |