You should always use a reference point such as (0,0) to determine which side of the line to shade. For example we have the equation y>2x-1 we then use the point (0,0) by substituting the point in the equation.
y>2x-1 -----> 0>2*0-1
we then solve and make sure the point satisfies the inequality.
0>2*0-1 ------> 0-1=-1 ----> 0>-1
We see that the point does satisfy the equation so we shade whatever side of the line that includes the point (0,0)
