14.最简二次根式$\sqrt{4x-8}$与$\sqrt{32}$是同类二次根式,则x等于( )
| A. | $\frac{5}{2}$ | B. | 10 | C. | 2 | D. | 4 |
13.下列方程中,两根之和是3的是( )
| A. | x2-3x+$\frac{5}{2}$=0 | B. | -x2+3x+$\frac{5}{2}$=0 | C. | x2+3x-$\frac{5}{2}$=0 | D. | x2+3x+$\frac{5}{2}$=0 |
12.下列方程适合用求根公式法解的是( )
| A. | (x-3)2=2 | B. | 325x2-326x+1=0 | C. | x2-100x+2500=0 | D. | 2x2+3x-1=0 |
9.y=x2-2x-3的顶点坐标和对称轴( )
| A. | (-1,-4),直线x=-1 | B. | (1,-4),直线x=1 | C. | (-1,4),直线x=-1 | D. | (1,4),直线x=1 |
8.将y=x2向右平移1个单位,再向下平移2单位后,所得表达式是( )
0 293137 293145 293151 293155 293161 293163 293167 293173 293175 293181 293187 293191 293193 293197 293203 293205 293211 293215 293217 293221 293223 293227 293229 293231 293232 293233 293235 293236 293237 293239 293241 293245 293247 293251 293253 293257 293263 293265 293271 293275 293277 293281 293287 293293 293295 293301 293305 293307 293313 293317 293323 293331 366461
| A. | y=(x-1)2+2 | B. | y=(x+1)2+2 | C. | y=(x-1)2-2 | D. | y=(x+1)2-2 |