Alexandra and Karissa are 261 miles apart, traveling towards each other. If Karissa travels 17 mph and Alexandra travels 12 mph how long until they meet?

Karissa - >. Distance = speed x time

Take the distance she travels to be x

X = 17t

Alexandra - > she would meet karissa at 261 - the x miles karissa travelled hence we get the equation

(261 - x) = 12t

Rearrange so x is the subject

X = 261 - 12t

Next set the two equations equal to each other so you get

17t = 261 - 12t

Now solve for t

29t = 261

Divide each side by 29 To get the Value of t

t = 9 hours (remember to take the units into account)