解:設(shè)?$y_1=m(x+3),$??$y_2=\frac {k}{x2}$?
所以?$y=y_1-y_2=m(x+3)-\frac {k}{x2}$?
由題意可得:?$\begin {cases}{m(1+3)-\frac {k}{(-1)2}=-2 } \\{m(-3+3)-\frac {k2}{(-3)}=2} \end {cases}$?
解得?$m=-5,$??$k=-18$?
所以?$y=-5(x+3)+\frac {18}{x2}$?
當(dāng)?$x=-1$?時,?$y=8$?