Given:
Two ships were 700 miles apart at midnight .
Let x be the speed of first ship and (x+30) be speed of second ship (faster ship).
The equation is,
[tex]\begin{gathered} Dis\tan ce=rate\times time \\ 10x+10(x+30)=700 \\ 10x+10x+300=700 \\ 20x=700-300 \\ 20x=400 \\ x=\frac{400}{20} \\ x=20 \end{gathered}[/tex]Answer: the speed of first ship ( slower) is 20 miles and the speed of second ship ( faster) is 20+30=50 miles.