13.下列函数关系式中,y不是x的函数的是( )
| A. | y=-x | B. | |y|=2x | C. | y=|2x| | D. | y=2x2+4 |
11.$\frac{{a}^{2}+a-2}{{a}^{2}+3a+2}$•5(a+1)2等于( )
| A. | a2+2a+1 | B. | 5a2+10 a+5 | C. | 5a2-1 | D. | 5a2-5 |
10.计算 $\frac{{x}^{2}-5x+6}{{x}^{2}-1}$÷$\frac{x-3}{{x}^{2}+x}$的结果是( )
| A. | $\frac{x(x-1)}{x-2}$ | B. | $\frac{x(x-2)}{x-1}$ | C. | $\frac{x-2}{x(x-1)}$ | D. | $\frac{x-1}{x(x-2)}$ |
9.已知圆柱的底面半径为3cm,母线长为5cm,则圆柱的侧面积是( )
0 291165 291173 291179 291183 291189 291191 291195 291201 291203 291209 291215 291219 291221 291225 291231 291233 291239 291243 291245 291249 291251 291255 291257 291259 291260 291261 291263 291264 291265 291267 291269 291273 291275 291279 291281 291285 291291 291293 291299 291303 291305 291309 291315 291321 291323 291329 291333 291335 291341 291345 291351 291359 366461
| A. | 30 cm 2 | B. | 30π cm 2 | C. | 15 cm 2 | D. | 15π cm 2 |