The sides of an equilateral triangle are given by the expressions x+y, 2y-1 and 3y-2x+1. Find the values of x and y.

This question test knowledge of the geometry of equilateral triangles and the students ability to solve linear equations.
First we note that an equilateral triangle has equal sides. Then we can write that x+y = 2y-1 and rearranging we find that x = y-1. Further we know that 2y-1 = 3y-2x+1 and rearranging we find that y = 2x -2. We then substitute this into the first equation we found so that x = (2x-2)-1 and rearranging once again we find that x = 3. Substituting this into y = 2x-2, we find that y = 4.