16.化简$\frac{\sqrt{2}+\sqrt{6}}{\sqrt{2+\sqrt{3}}}$的结果是( )
| A. | 1 | B. | $\sqrt{3}$ | C. | 2 | D. | 4 |
13.化简$\sqrt{{x}^{4}+{x}^{2}{y}^{2}}$的结果是( )
| A. | x2+xy | B. | |x|$\sqrt{{x}^{2}+{y}^{2}}$ | C. | xy$\sqrt{{x}^{2}+1}$ | D. | x2y$\sqrt{x+1}$ |
10.若$\sqrt{4-{a}^{2}}$=$\sqrt{{a}^{2}-4}$,则a的值为( )
0 283485 283493 283499 283503 283509 283511 283515 283521 283523 283529 283535 283539 283541 283545 283551 283553 283559 283563 283565 283569 283571 283575 283577 283579 283580 283581 283583 283584 283585 283587 283589 283593 283595 283599 283601 283605 283611 283613 283619 283623 283625 283629 283635 283641 283643 283649 283653 283655 283661 283665 283671 283679 366461
| A. | 0 | B. | ±2 | C. | ±4 | D. | 2 |