Hi, I'm trying to figure out how to get a pole-zero map from a difference equation. It's for a lecture I've missed but the notes I have skip over them.



I have some difference equations and sketches of solutions but I can't figure out the relationship between them:


y(n)=134x(n)+06y(n−1)+09y(n−2)


Gives a zero at (0,0), and poles at approx (0.2, 0.9) and (0.2, -0.9)


y(n)=2x(n)−x(n−1)−03y(n−1)


Gives a zero at (0, 0.5) and a pole at (0, -0.3)


y(n)=x(n)−08y(n−1)−08y(n−2)


Gives a zero at (0, 0) and complex conjugate poles at approximately (-0.4, 0.8) and (-0.4, -0.8)


Any help appreciated, even hints. Thanks