9.点M(-2,3)关于x轴对称点的坐标为( )
| A. | (-2,-3) | B. | (2,-3) | C. | (-3,-2) | D. | (2,3) |
8.若直线ax+2y+2=0与直线3x-y-2=0平行,那么系数a等于( )
| A. | -3 | B. | -6 | C. | -$\frac{3}{2}$ | D. | $\frac{2}{3}$ |
4.
如图,∠ABC=∠CDB=90°,BC=3,AC=5,如果△ABC与△CDB相似,那么BD的长( )
0 312911 312919 312925 312929 312935 312937 312941 312947 312949 312955 312961 312965 312967 312971 312977 312979 312985 312989 312991 312995 312997 313001 313003 313005 313006 313007 313009 313010 313011 313013 313015 313019 313021 313025 313027 313031 313037 313039 313045 313049 313051 313055 313061 313067 313069 313075 313079 313081 313087 313091 313097 313105 366461
| A. | $\frac{12}{5}$ | B. | $\frac{15}{4}$ | C. | $\frac{9}{5}$ | D. | $\frac{12}{5}$或$\frac{9}{5}$ |