11.
如图,在?ABCD中,E、F分别是边AD、BC的中点,AC分别交BE、DF于点M、N,下面结论错误的是( )
| A. | △ABM≌△CDN | B. | AC=3AM | C. | DN=2NF | D. | BM=3ME |
9.在-$\frac{π}{3}$,$\frac{22}{7}$,$\sqrt{12}$,-$\root{3}{27}$,2$\frac{1}{2}$,6.101001000100001(1后面的0依次多1个)中,无理数有( )
| A. | 2个 | B. | 3个 | C. | 4个 | D. | 5个 |
8.某商店出售一种商品,若每件10元,则每天可销售50件,售价每降低1元,可多买6件,要使该商品每天的销售额(总售价)为504元,设每件降低x元,则可列方程为( )
| A. | (50+x)(10-x)=504 | B. | 50(10-x)=504 | C. | (10-x)(50+6x)=504 | D. | (10-6x)(50+x)=504 |
4.化简后能与$\sqrt{2}$是同类二次根式为( )
| A. | $\sqrt{24}$ | B. | $\sqrt{16}$ | C. | $\sqrt{\frac{1}{4}}$ | D. | $\frac{1}{\sqrt{2}}$ |
3.方程x-y=6的一组解是( )
0 285426 285434 285440 285444 285450 285452 285456 285462 285464 285470 285476 285480 285482 285486 285492 285494 285500 285504 285506 285510 285512 285516 285518 285520 285521 285522 285524 285525 285526 285528 285530 285534 285536 285540 285542 285546 285552 285554 285560 285564 285566 285570 285576 285582 285584 285590 285594 285596 285602 285606 285612 285620 366461
| A. | $\left\{\begin{array}{l}{x=1}\\{y=-5}\end{array}\right.$ | B. | $\left\{\begin{array}{l}{x=0}\\{y=6}\end{array}\right.$ | C. | $\left\{\begin{array}{l}{x=-1}\\{y=7}\end{array}\right.$ | D. | $\left\{\begin{array}{l}{x=-2}\\{y=4}\end{array}\right.$ |