Question 1205745
A description is given and then suddenly an equation system is shown.
Catch-Up.


Trashia 40 mph
going half hour before Karissa begins from same place, same direction
{{{40*(1/2)}}}, distance traveled


Karissa 60 mph
t, time for Karissa to catch up.


Karissa approaches at rate of {{{60-40}}} mph to Trashia.
At Karissa's start, distance of separation is  40(1/2) miles.


{{{highlight_green((60-40)t=40(1/2))}}}

{{{20t=20}}}

{{{highlight(t=1)}}}