Solve: $|2x - 1| = |3x + 5|$. write your answers as a list of numbers, separated by commas,
e. g. "23, 19" (but without the quotes).

First, disregard the sign for absolute value and solve for x. 

2x - 1 = 3x + 5
2x - 3x = 5 + 1
-x = 6
x = -6

Now, you have to interpret the absolute value. The absolute value of x is always the positive version of whatever the number is. Since x = -6, its absolute value is 6. Therefore, the possible value for x is only one, which is 6.