Are you asking how you can verify that a point is on that plane? That is easy: Just plug in the values of x, y and z of the point into the equation above and see if it holds. In your case, you have x=0, y=0 and z=2/5.
Or, if you are only concerned with finding a single point on the plane, choose whatever numbers you like for any two of x, y, and z, put them into the equation, and solve for the remaining variable. For example, putting x= 0, y= 0 into the equation gives so that . Or, if you put x= 0, z= 2/5 into the equation you get which reduces to .