18.下列多项式中,能分解因式的是( )
| A. | x2+2x | B. | x2-y | C. | x2+y2 | D. | x2-xy+y2 |
12.下列式子中,计算结果为x2+2x-3的是( )
| A. | (x-1)(x+3) | B. | (x+1)(x-3) | C. | (x-1)(x-3) | D. | (x+1)(x+3) |
11.对多项式3x2-3x因式分解,提取的公因式为( )
0 284629 284637 284643 284647 284653 284655 284659 284665 284667 284673 284679 284683 284685 284689 284695 284697 284703 284707 284709 284713 284715 284719 284721 284723 284724 284725 284727 284728 284729 284731 284733 284737 284739 284743 284745 284749 284755 284757 284763 284767 284769 284773 284779 284785 284787 284793 284797 284799 284805 284809 284815 284823 366461
| A. | 3 | B. | x | C. | 3x | D. | 3x2 |