Solve the system of differential equations using
elimination:
x1'(t) = x2
x2'(t) = 2x3 - 2x4 +
3e-t + 2
x3' (t) = - (½)x2 + (¼) x4 -
(¼)
x4' (t) = x5
x5' (t) = -x2 + 2x3 -
x5