Note: continuous time signals x(t), time t = R+; and its Laplace transform result is (s) where s Z. Classify the following systems as linear or nonlinear, time-invariant or time-variant, causal or non-causal, dynamic or static. You can treat y(t) as the output and u(t) as the input. (a) (t) + ty(t) = 4u(t + 3) (d) y(t) = 4sin(t)u(t) (b) (t) +5y(t) = 4u(t) (e) e(t) + y(t + 1) = u(t) (c) y(t 1)u(t) = 1