*8. consider a lti system with unit impulse response, h(t) = e-3tu(t). using direct integration technique for finding convolution, find its zero-state response due to an input, x(t) = u(t) (which is called unit step response of the system). also, from your answer above, write down its response due to an input of the form, x(t) = 2δ(t) – 4u(t). [hint: use principle of superposition]