Alright, so we can start by dividing -2 from both sides, getting |5y-1|=20. Then, since 5y-1 is in an absolute value, 5y-1 is either 20 or -20. In 5y-1=20, we can add one to both sides, getting 5y=21 and y=21/5. In 5y-1=-20, we can add one again, getting 5y=-19 and y=-19/5.
If you have any more equations, make sure to plug both numbers in to check, but otherwise y has two answers , which are -19/5 and 21/5.