Question 917069
RT=D rate time distance, uniform rates rule for travel

Let t be amount of time Tim drove to catchup to Dora;
Let d be the distance that both Tim and Dora traveled when Tim reaches Dora.


______________________speed________time________distance
Dora___________________75__________t+1__________d
Tim____________________90___________t___________d


The use of this travel uniform rates rule gives {{{75(t+1)=d}}}  and {{{90*t=d}}}.  Both are formula for the same distance, d.


{{{highlight(75(t+1)=90t)}}}