13.下列运算正确的是( )
| A. | $\sqrt{2}•\sqrt{3}$=$\sqrt{5}$ | B. | ($\frac{1}{2}$)-2=4 | C. | 3a2-2a2=1 | D. | a6÷a3=a2 |
9.在-3、0、π、$\sqrt{3}$这四个数中,最小的有理数是( )
| A. | 0 | B. | -3 | C. | π | D. | $\sqrt{3}$ |
6.下面四个二次根式中,最简二次根式是( )
0 285392 285400 285406 285410 285416 285418 285422 285428 285430 285436 285442 285446 285448 285452 285458 285460 285466 285470 285472 285476 285478 285482 285484 285486 285487 285488 285490 285491 285492 285494 285496 285500 285502 285506 285508 285512 285518 285520 285526 285530 285532 285536 285542 285548 285550 285556 285560 285562 285568 285572 285578 285586 366461
| A. | $\sqrt{{x}^{2}+1}$ | B. | $\sqrt{\frac{1}{2}}$ | C. | 2$\sqrt{8}$ | D. | $\sqrt{3{x}^{3}}$(x≥0) |