20.
如图,直线AB、CD交于O,OE是∠BOC的平分线且∠BOE=50度,那么∠AOE=( )度.
| A. | 80 | B. | 100 | C. | 130 | D. | 150 |
19.下列方程组中,是二元一次方程组的是( )
| A. | $\left\{\begin{array}{l}{\frac{1}{x}+y=3}\\{2x-1=0}\end{array}\right.$ | B. | $\left\{\begin{array}{l}{3x-2=0}\\{2y+1=0}\end{array}\right.$ | C. | $\left\{\begin{array}{l}{x+y=0}\\{y-z=7}\end{array}\right.$ | D. | $\left\{\begin{array}{l}{{x}^{2}+y=-2}\\{2x-y=0}\end{array}\right.$ |
18.∠1与∠2是内错角的是( )
| A. | B. | C. | D. |
17.在反比例函数y=$\frac{1-2m}{x}$,图象分布在一三象限,则m的取值范围是( )
0 307816 307824 307830 307834 307840 307842 307846 307852 307854 307860 307866 307870 307872 307876 307882 307884 307890 307894 307896 307900 307902 307906 307908 307910 307911 307912 307914 307915 307916 307918 307920 307924 307926 307930 307932 307936 307942 307944 307950 307954 307956 307960 307966 307972 307974 307980 307984 307986 307992 307996 308002 308010 366461
| A. | m<0 | B. | m>0 | C. | m<$\frac{1}{2}$ | D. | m>$\frac{1}{2}$ |