7.
如图,E,F在线段BC上,AB=DC,AE=DF,BF=CE,下列结论不一定成立的是( )
| A. | ∠B=∠C | B. | AF=FD | C. | AE=DF | D. | AB∥DC |
6.若一次函数y=3x+6与一次函数y=2x-4的图象的交点为(a,b),则$\left\{\begin{array}{l}{x=a}\\{y=b}\end{array}\right.$是下列哪个方程组的解( )
| A. | $\left\{\begin{array}{l}{3x-y=-6}\\{2x-y-4=0}\end{array}\right.$ | B. | $\left\{\begin{array}{l}{3x+6+y=0}\\{2x-y-y=0}\end{array}\right.$ | ||
| C. | $\left\{\begin{array}{l}{y-3x=6}\\{2x+y=-4}\end{array}\right.$ | D. | $\left\{\begin{array}{l}{3x-y=6}\\{2x-y=4}\end{array}\right.$ |
5.在班委会干部选举中,某同学的票没有超过半数,这是指这位同学的票是频率( )
| A. | 大于0.5 | B. | 等于0.5 | C. | 小于或等于0.5 | D. | 大于或等于0.5 |
4.
如图,△ABC≌△CDA,下列结论错误的是( )
| A. | ∠DAC=∠BCA | B. | ∠ADC=∠ACB | C. | ∠B=∠D | D. | AD=BC |
3.一次函数y=kx+b(k>0,b>0)的图象经过( )
| A. | 一、二、三象限 | B. | 一、二、四象限 | C. | 一、三、四象限 | D. | 二、三、四象限 |
2.直线y=kx+3过点(-2,0),则k的值是( )
| A. | -2 | B. | -$\frac{2}{3}$ | C. | $\frac{3}{2}$ | D. | -3 |
1.下列说法正确的是( )
| A. | $\frac{1}{81}$的立方根是$\frac{1}{9}$ | B. | -$\frac{1}{81}$的平方根是$\frac{1}{9}$ | ||
| C. | $\frac{1}{27}$的算术平方根是$\frac{1}{3}$ | D. | -$\frac{1}{27}$的立方根是-$\frac{1}{3}$ |
20.在实数:5.2,-$\frac{2}{3}$,0.028,$\sqrt{3}$,$\root{3}{10}$,3$\frac{1}{2}$,3.14中,无理数的个数是( )
0 309597 309605 309611 309615 309621 309623 309627 309633 309635 309641 309647 309651 309653 309657 309663 309665 309671 309675 309677 309681 309683 309687 309689 309691 309692 309693 309695 309696 309697 309699 309701 309705 309707 309711 309713 309717 309723 309725 309731 309735 309737 309741 309747 309753 309755 309761 309765 309767 309773 309777 309783 309791 366461
| A. | 1个 | B. | 2个 | C. | 3个 | D. | 4个 |