P-6.19 For the cascade configuration in Fig. P-6.17, the two systems are defined by H(e) = 1+2e-jo. +e-j02 and h[n] = 8[n] - 8[n 1] +8[n-2] - 8[n - 3] (a) Determine the frequency response H (e) for the overall cascade system (i.e., from input x[n] to output y[n]). Simplify your answer as much as possible. (b) Determine and plot the impulse response h[n] of the overall cascade system. (c) Write down the difference equation that relates y[n] to x[n].