Solving the equation found in step 1 for x, we have:
[tex]\begin{gathered} 2320=8x+320 \\ 8x=2320-320 \\ 8x=2000 \\ x=\frac{2000}{8} \\ x=250\text{ mph} \end{gathered}[/tex]Therefore the speed of one plane is 250 mph and the speed of the second plane is 330 mph.