3.下列从左边到右边的变形,属于因式分解的是( )
| A. | (x+1)(x-1)=x2-1 | B. | x2-2x+1=x(x-2)+1 | C. | x2-4y2=(x+4y)(x-4y) | D. | x2-x-6=(x+2)(x-3) |
16.下列计算正确的是( )
0 283617 283625 283631 283635 283641 283643 283647 283653 283655 283661 283667 283671 283673 283677 283683 283685 283691 283695 283697 283701 283703 283707 283709 283711 283712 283713 283715 283716 283717 283719 283721 283725 283727 283731 283733 283737 283743 283745 283751 283755 283757 283761 283767 283773 283775 283781 283785 283787 283793 283797 283803 283811 366461
| A. | $\sqrt{2}×\sqrt{3}=6$ | B. | $\sqrt{2}$+$\sqrt{3}$=$\sqrt{5}$ | C. | $3\sqrt{2}$-$\sqrt{2}$=$\sqrt{5}$ | D. | $\sqrt{6}÷\sqrt{2}=\sqrt{3}$ |