14.下列计算正确的是( )
| A. | 2a+3a=5a2 | B. | a2•a3=a6 | C. | a6÷a2=a3 | D. | (a2)3=a6 |
13.把多项式2x3y-x2y2-6x2y分解因式时,应提取的公因式为( )
| A. | x2y | B. | xy2 | C. | 2x3y | D. | 6x2y |
10.下列计算正确的是( )
| A. | $\sqrt{6}-\sqrt{3}=\sqrt{3}$ | B. | $\sqrt{6}÷\sqrt{3}=\sqrt{2}$ | C. | $\sqrt{{{(-3)}^2}}=-3$ | D. | $\sqrt{9}=±3$ |
7.计算$\sqrt{8}×\sqrt{2}$的结果是( )
0 285404 285412 285418 285422 285428 285430 285434 285440 285442 285448 285454 285458 285460 285464 285470 285472 285478 285482 285484 285488 285490 285494 285496 285498 285499 285500 285502 285503 285504 285506 285508 285512 285514 285518 285520 285524 285530 285532 285538 285542 285544 285548 285554 285560 285562 285568 285572 285574 285580 285584 285590 285598 366461
| A. | $\sqrt{10}$ | B. | 4 | C. | 8 | D. | ±4 |