<PRE><B>Question 970515</B>
On a road trip, a family drives one third of the way on the first day.
 After driving 200 miles on the second day, they are seven ninths of the way to their destination. How many miles is there trip?
:
Here is the equation for what you basically said
let d = total dist of the trip
d = {{{1/3}}}d + 200 + {{{2/9}}}d
d = {{{3/9}}}d + 200 + {{{2/9}}}d
d = {{{5/9}}}d + 200 
d - {{{5/9}}}d = 200
{{{4/9}}}d = 200
d = 200 * {{{9/4}}}
cancel 4
d = 50 * 9
d = 450 mi</PRE>