9.下列运算正确的是( )
0 284606 284614 284620 284624 284630 284632 284636 284642 284644 284650 284656 284660 284662 284666 284672 284674 284680 284684 284686 284690 284692 284696 284698 284700 284701 284702 284704 284705 284706 284708 284710 284714 284716 284720 284722 284726 284732 284734 284740 284744 284746 284750 284756 284762 284764 284770 284774 284776 284782 284786 284792 284800 366461
| A. | 4a-a=3 | B. | a6÷a3=a3 | C. | (ab)2=ab2 | D. | (a-b)2=a2-b2 |