Question 959892
_________________________speed____________time___________distance
SLOWER___________________200______________t______________d
FASTER___________________350______________T______________D


Your description indicated that d=D.  Choose these to be equal or assign a new variable to BOTH:
L=d=D;


_________________________speed____________time___________distance
SLOWER___________________200______________t______________L
FASTER___________________350______________T______________L


Form a system  {{{system(200t=L,350T=L)}}}.


{{{200t=350T}}}


{{{t=(350/200)T}}}


{{{highlight(t=(7/4)T)}}}