Algebra word problem?

This is a distance = rate times time problem, or d=rt. Erica and Aisha went the same distance so their rt=rt because their d=d We neet to express their time in values of rate so that there is only one variable. So Erica traveled 80km/h and Aisha traveled 100 km/h. Erica left for example 12 o'clock and Aisha left at 11 o'clock. So we can say that 80t=100(t-1) Distribute the 100 and you have 80t=100t-100. Add 100 to both sides and subtract 80t from both sides. 100=20t. Divide by 20. 5=t t is the time so we can say that Aisha met Erica up the road 5 hours after Erica left, or 4 hours after Aisha left, because the expression for Aisha was t-1 and the expression for Erica was just t.