Continuous-Time System:
a1 = 8, a0 = 21, b1 = 9, b0 = 8, 

Your excitation signal x(t) consists of straight lines connecting these points.
It has been zero up until the first time and is zero after the last time.

t = 1.15448, x(t) = 0
t = 1.15448, x(t) = -6
t = 2.08458, x(t) = -6
t = 2.08458, x(t) = -7
t = 3.10044, x(t) = -7
t = 3.10044, x(t) = 4
t = 3.149, x(t) = 4
t = 3.149, x(t) = 2
t = 6.36468, x(t) = 2
t = 6.36468, x(t) = 7
t = 8.11806, x(t) = 7
t = 8.11806, x(t) = -5
t = 9.36052, x(t) = -5
t = 9.36052, x(t) = 0
t = 16.0823, x(t) = 0

Discrete-Time System:
a0 = -20, a1 = -18, b0 = -28, b1 = -18, 
0 <= n < 7,  x[n] = 0
7 <= n < 9,  x[n] = 17
9 <= n < 13,  x[n] = 0
13 <= n < 14,  x[n] = 0
14 <= n < 16,  x[n] = -4
16 <= n < 27,  x[n] = 0

x[n] has been zero up until the first time and is zero after the last time.