9.-$\frac{3}{4}$的倒数是( )
| A. | $\frac{3}{4}$ | B. | $\frac{4}{3}$ | C. | $-\frac{3}{4}$ | D. | $-\frac{4}{3}$ |
6.
如图所示,在一块长为22m,宽为17m的矩形地面上,要修建同样宽的两条互相垂直的道路(两条道路各与矩形的一条边平行),若剩余部分种上草坪,使草坪的面积为300m2,则所修道路的宽度为( )m.
| A. | 4 | B. | 3 | C. | 2 | D. | 1 |
5.用配方法解一元二次方程x2+4x-3=0时,原方程可变形为( )
0 293828 293836 293842 293846 293852 293854 293858 293864 293866 293872 293878 293882 293884 293888 293894 293896 293902 293906 293908 293912 293914 293918 293920 293922 293923 293924 293926 293927 293928 293930 293932 293936 293938 293942 293944 293948 293954 293956 293962 293966 293968 293972 293978 293984 293986 293992 293996 293998 294004 294008 294014 294022 366461
| A. | (x+2)2=1 | B. | (x+2)2=19 | C. | (x+2)2=13 | D. | (x+2)2=7 |