Z transform and its Application on Digital Signal Processing related Questions and Answers

Question :   Which of the following justifies the linearity property of z-transform?[x(n)↔X(z)]. 1. x(n)+y(n) ↔X(z)Y(z) 2. x(n)+y(n) ↔X(z)+Y(z) 3. x(n)y(n) ↔X(z)+Y(z) 4. x(n)y(n) ↔X(z)Y(z) Answer :   2 - x(n)+y(n) ↔X(z)+Y(z)