3.下列等式由左边至右边的变形中,属于因式分解的是( )
| A. | x2+5x-1=x(x+5)-1 | B. | x2-4+3x=+3x | C. | x2-9=(x+3)(x-3) | D. | (x+2)(x-2)=x2-4 |
1.下列计算正确的是( )
0 284663 284671 284677 284681 284687 284689 284693 284699 284701 284707 284713 284717 284719 284723 284729 284731 284737 284741 284743 284747 284749 284753 284755 284757 284758 284759 284761 284762 284763 284765 284767 284771 284773 284777 284779 284783 284789 284791 284797 284801 284803 284807 284813 284819 284821 284827 284831 284833 284839 284843 284849 284857 366461
| A. | m2•m3=m5 | B. | (-2)3=8 | C. | (a+b)2=a2+b2 | D. | 3-2=-9 |