9.若方程x-3my=2x-4是关于x、y的二元一次方程,则m为( )
| A. | m≠0 | B. | m≠1 | C. | m≠2 | D. | m≠3 |
6.计算-6a3b2÷2a2b的结果是( )
| A. | -3ab2 | B. | -3ab | C. | 3ab | D. | 3ab2 |
5.
如图,四边形ABCD是菱形,AC=8,DB=6,DH⊥AB于H,则DH=( )
0 284650 284658 284664 284668 284674 284676 284680 284686 284688 284694 284700 284704 284706 284710 284716 284718 284724 284728 284730 284734 284736 284740 284742 284744 284745 284746 284748 284749 284750 284752 284754 284758 284760 284764 284766 284770 284776 284778 284784 284788 284790 284794 284800 284806 284808 284814 284818 284820 284826 284830 284836 284844 366461
| A. | $\frac{24}{5}$ | B. | $\frac{12}{5}$ | C. | 4 | D. | 8 |