2x-y=6,令y=0,x=3,
所以c=3,c/a=3/a=2,
a=3/2 b^2=c^2-a^2=9-9/4=27/4
双曲线为x^2/(9/4)-y^2 /(27/4)=1
或2x-y=6,令x=0,y=-6
所以c=6,6/a=2,a=3
b^2=c^2-a^2=36-9=27
双曲线为y^2/9-x^2/27=1