17.若关于x、y的二元一次方程组$\left\{\begin{array}{l}{2x+y=3k-1}\\{x+2y=-2}\end{array}\right.$的解满足x+y≤1,求k的取值范围.
13.
如图所示,有一块直角三角形纸片,∠C=90°,AC=2,BC=$\frac{3}{2}$,将斜边AB翻折,使点B落在直角边AC的延长线上的点E处,折痕为AD,则CE的长为( )
| A. | $\frac{1}{2}$ | B. | $\frac{3}{4}$ | C. | 1 | D. | $\frac{3}{2}$ |
12.要使二次根式$\sqrt{5-2x}$有意义,则x的取值范围是( )
0 282254 282262 282268 282272 282278 282280 282284 282290 282292 282298 282304 282308 282310 282314 282320 282322 282328 282332 282334 282338 282340 282344 282346 282348 282349 282350 282352 282353 282354 282356 282358 282362 282364 282368 282370 282374 282380 282382 282388 282392 282394 282398 282404 282410 282412 282418 282422 282424 282430 282434 282440 282448 366461
| A. | x$>\frac{5}{2}$ | B. | x$≥\frac{2}{5}$ | C. | x$≤\frac{5}{2}$ | D. | x$≤\frac{2}{5}$ |