2.当|k-2b|+$\sqrt{k+b-3}$=0时,直线y=kx+b经过点( )
| A. | (-1,-1) | B. | (-1,1) | C. | (-1,-3) | D. | (-1,3) |
19.若一次函数y=kx+b的图象经过点P(-2,3),则2k-b的值为( )
| A. | 2 | B. | -2 | C. | 3 | D. | -3 |
14.计算:$\frac{4}{{x}^{2}-4}$-$\frac{1}{x-2}$的正确结果是( )
0 282789 282797 282803 282807 282813 282815 282819 282825 282827 282833 282839 282843 282845 282849 282855 282857 282863 282867 282869 282873 282875 282879 282881 282883 282884 282885 282887 282888 282889 282891 282893 282897 282899 282903 282905 282909 282915 282917 282923 282927 282929 282933 282939 282945 282947 282953 282957 282959 282965 282969 282975 282983 366461
| A. | -$\frac{1}{x+2}$ | B. | 1-x | C. | 1 | D. | -1 |