Continuous-Time System:
a1 = 8, a0 = 21, b1 = 7, 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 = 4.47821, x(t) = 0
t = 4.47821, x(t) = -10
t = 5.33492, x(t) = -10
t = 5.33492, x(t) = 6
t = 7.55473, x(t) = 6
t = 7.55473, x(t) = 8
t = 8.81042, x(t) = 8
t = 8.81042, x(t) = -15
t = 8.85353, x(t) = -15
t = 8.85353, x(t) = 0
t = 14.4435, x(t) = 0

Discrete-Time System:
a0 = 10, a1 = 9, b0 = 9, b1 = -3, 
0 <= n < 4,  x[n] = 0
4 <= n < 7,  x[n] = -2
7 <= n < 9,  x[n] = 23
9 <= n < 10,  x[n] = -9
10 <= n < 11,  x[n] = -3
11 <= n < 13,  x[n] = -13
13 <= n < 26,  x[n] = 0

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