Determine the distance covered by the first car in 2 hours.
[tex]\begin{gathered} d_1=90\cdot2 \\ =180 \end{gathered}[/tex]Determine the distance covered by second car in 2 hours.
[tex]\begin{gathered} d_2=80\cdot2 \\ =160 \end{gathered}[/tex]Determine the total distance covered by both cars in 2 hours.
[tex]\begin{gathered} d=d_1+d_2 \\ =180+160 \\ =340 \end{gathered}[/tex]The distance left between them after two hours is difference of 1304 and 340. So left distance between them is,
[tex]\begin{gathered} D=1304-340 \\ =964 \end{gathered}[/tex]Thus 964 km left between them after 2 hours.