7.已知:点A(a,b),B(a+1,b-2)均在正比例函数y=kx(k≠0)的图象上,则k值为( )
0 282766 282774 282780 282784 282790 282792 282796 282802 282804 282810 282816 282820 282822 282826 282832 282834 282840 282844 282846 282850 282852 282856 282858 282860 282861 282862 282864 282865 282866 282868 282870 282874 282876 282880 282882 282886 282892 282894 282900 282904 282906 282910 282916 282922 282924 282930 282934 282936 282942 282946 282952 282960 366461
| A. | -1 | B. | -2 | C. | -3 | D. | -4 |