Problem 4. Consider two discrete-time LTI systems in series. Overall System x[n]} z[n] y[n] System 1 System 2 (a) System 1 is described by the following difference equation z[n] = 2n 1] + r[n] xn 6] (1) Determine and plot (stem-plot) the impulse response h (n) of System 1. (b) The frequency response |Hi(w)| of System 1 is the DTFT of the impulse response hi[n]. Plot the magnitude, Hi(w)), of the frequency response of System 1 over -