Optimization – Resolving an entire program by cutting a plane

I have IP, that I first solved the LP-relaxation and obtained an optimum that is not a whole number. In the optimal table, I selected the following equation

$$x_2 + 0.25x_3 + 0.25 x_4 = 2.5$$

where $$x_3, x_4 geq 0$$ they are varaibles loose and $$x_2 geq 0$$. I want to generate a cut of this. The technique I learn is to separate integers on one side of the equation and rational on the other. So, we have

$$x_2 + x_3 – 0.75 x_3 + x_4 – 0.75 x_4 = 3 – 0.5$$

whose yields

$$x_2 + x_3 + x_4 – 3 = 0.75 x_3 + 0.75 x_4 – 0.5$$

Now this is where I get stuck, how can I know if RHS is $$geq 0$$ or $$leq 0$$. As far as I can tell, $$x_2 + x_3 + x_4 -3$$ We do not know if it is positive or negative.