You can
put this solution on YOUR website!D=R*T THEN DISTANCE GOING IS R*5 AND THE SAME DISTANCE RETURNING IS (R+5)4 OR
5R=4(R+5) OR 5R=4R+20 OR R=20 MPH GOING FOR 5 HOURS EQUALS 100 MILES.
THE RETURN TRIP WAS @ 25 MPH FOR 4 HOURS THUS 25*4=100 MILES.