16.若分式$\frac{x-2}{x+2}$的值为0,则( )
| A. | x=0 | B. | x=2 | C. | x=-2 | D. | x≠-2 |
14.
如图,扇形AOB的圆心角为90°,四边形OCDE是边长为1的正方形,点C、E、D分别在OA、OB、$\widehat{AB}$上,过A作AF⊥ED交ED的延长线于点F,那么图中阴影部分的面积为( )
| A. | $\frac{\sqrt{2}}{2}$ | B. | $\sqrt{2}$-1 | C. | 2-$\sqrt{2}$ | D. | $\sqrt{2}$ |
13.
如图是二次函数y=ax2+bx+c的部分图象,y<0时自变量x的取值范围是( )
| A. | -1<x<5 | B. | x>5 | C. | x<-1且x>5 | D. | x<-1或x>5 |
12.已知2x6y2和-$\frac{1}{3}$x3myn是同类项,则9m2-5mn-17的值是( )
0 285916 285924 285930 285934 285940 285942 285946 285952 285954 285960 285966 285970 285972 285976 285982 285984 285990 285994 285996 286000 286002 286006 286008 286010 286011 286012 286014 286015 286016 286018 286020 286024 286026 286030 286032 286036 286042 286044 286050 286054 286056 286060 286066 286072 286074 286080 286084 286086 286092 286096 286102 286110 366461
| A. | -1 | B. | -2 | C. | -3 | D. | -4 |