16.下列运算不能运用平方差公式的是( )
| A. | (2m+3)(2m-3) | B. | (-2m+3)(2m-3) | C. | (-2m-3)(2m-3) | D. | (-2m+3)(-2m-3) |
15.已知∠α=55°,则它的补角是( )
| A. | 135° | B. | 125° | C. | 45° | D. | 35° |
12.
如图,平面直角坐标系xOy中,矩形OABC的边OA、OC分别落在x、y轴上,点B坐标为(6,4),反比例函数y=$\frac{6}{x}$的图象与AB边交于点D,与BC边交于点E,连结DE,将△BDE沿DE翻折至△B'DE处,点B'恰好落在正比例函数y=kx图象上,则k的值是( )
| A. | $-\frac{2}{5}$ | B. | $-\frac{1}{21}$ | C. | $-\frac{1}{5}$ | D. | $-\frac{1}{24}$ |
7.已知不等式组$\left\{\begin{array}{l}{\frac{2x-1}{3}>1}\\{x>m}\end{array}\right.$的解集为x>2,则( )
0 296617 296625 296631 296635 296641 296643 296647 296653 296655 296661 296667 296671 296673 296677 296683 296685 296691 296695 296697 296701 296703 296707 296709 296711 296712 296713 296715 296716 296717 296719 296721 296725 296727 296731 296733 296737 296743 296745 296751 296755 296757 296761 296767 296773 296775 296781 296785 296787 296793 296797 296803 296811 366461
| A. | m>2 | B. | m<2 | C. | m=2 | D. | m≤2 |