11.与$-3\frac{1}{4}$相等的是( )
| A. | $-\frac{3}{4}$ | B. | (-3)×4 | C. | -3-$\frac{1}{4}$ | D. | -3+$\frac{1}{4}$ |
10.3x=4y(xy≠0),则下列各式中不成立的( )
| A. | $\frac{x+y}{y}$=$\frac{7}{3}$ | B. | $\frac{x-y}{y}$=$\frac{1}{3}$ | C. | $\frac{x}{x-y}$=4 | D. | $\frac{x+1}{y+1}$=$\frac{5}{4}$ |
7.抛物线y=5x2先向上平移2个单位,再向右平移3个单位,所得的抛物线的解析式是( )
| A. | y=5(x+3)2+2 | B. | y=5(x-3)2+2 | C. | y=5(x+3)2-2 | D. | y=5(x-3)2-2 |
6.已知二次函数y=4(x-2)2+3与y=ax2开口方向相同,形状和大小也相同,则a的值为( )
| A. | 4 | B. | -4 | C. | 2 | D. | -2 |
5.抛物线y=4(x-3)2+7的顶点坐标是( )
| A. | (3,7) | B. | (-3,7) | C. | (3,-7) | D. | (-3,-7) |
4.如果二次函数y=ax2+bx,当x=1时,y=2;当x=-1时,y=4,则a,b的值是( )
| A. | a=3,b=-1 | B. | a=3,b=1 | C. | a=-3,b=1 | D. | a=-3,b=-1 |
3.一元二次方程x2-6x=-9的根的情况是( )
0 309774 309782 309788 309792 309798 309800 309804 309810 309812 309818 309824 309828 309830 309834 309840 309842 309848 309852 309854 309858 309860 309864 309866 309868 309869 309870 309872 309873 309874 309876 309878 309882 309884 309888 309890 309894 309900 309902 309908 309912 309914 309918 309924 309930 309932 309938 309942 309944 309950 309954 309960 309968 366461
| A. | 有两个相等的实数根 | B. | 有两个不相等实数根 | ||
| C. | 无实数根 | D. | 无法确定 |