18.下列各个运算中,能合并成一个根式的是( )
| A. | $\sqrt{12}$-$\sqrt{2}$ | B. | $\sqrt{18}$-$\sqrt{8}$ | C. | $\sqrt{8{a}^{2}}$+$\sqrt{2a}$ | D. | $\sqrt{{x}^{2}y}$+$\sqrt{x{y}^{2}}$ |
17.在多项式3x2y3z+4x5y2+6x4yz2中,各项的公因式是( )
0 282374 282382 282388 282392 282398 282400 282404 282410 282412 282418 282424 282428 282430 282434 282440 282442 282448 282452 282454 282458 282460 282464 282466 282468 282469 282470 282472 282473 282474 282476 282478 282482 282484 282488 282490 282494 282500 282502 282508 282512 282514 282518 282524 282530 282532 282538 282542 282544 282550 282554 282560 282568 366461
| A. | x2yz | B. | 12x5y3z2 | C. | 12x2yz | D. | x2y |