Question 323046
x=Emily's rate and y=Camille's rate.

They drive in opposite directions, so between them they travel 354 miles.

3x+3y=354

Now, if they go in the same direction, the difference is 18

3x-3y=18

There are the two equations to solve. Use Cramer's rule if you have to. But it can also be solved by substitution, elimination, rref,....