Using unilateral Z-transform to solve the following differ- ence equations: • • • • x[n+2]+x[n+1]+x[n] = u[n], y[0] = 1 and y[1] = 2. y[n 1] − 0.9y[n] = 0.05u[n + 1], y[0] = 0. - y[n+1] = −5y[n] + nu[n+1], y[0] = 0.