[ Eq(Derivative(x1, t), (1*k17*k1 + 1*k17*k2*x4 + 1*k17*k4*(1 - k3)*x2 + (-1)*k17*k6*x1*x3 + (-1)*k17*k5*x1 + (-1)*k17*k7*x1)/k17),
  Eq(Derivative(x2, t), ((-1)*k17*k4*(1 - k3)*x2 + 1*k17*k6*x1*x3 + (-1)*k17*k4*k3*x2 + (-1)*k17*k5*x2 + (-1)*k17*k7*x2)/k17),
  Eq(Derivative(x3, t), (1*k17*k4*k3*x2 + (-1)*k17*k5*x3 + (-1)*k17*k8*x3)/k17),
  Eq(Derivative(x4, t), ((-1)*k17*k2*x4 + 1*k17*k7*x1 + 1*k17*k7*x2 + (-1)*k17*k5*x4)/k17),
  Eq(Derivative(x5, t), (1*k18*k9 + 1*k18*k10*x8 + 1*k18*k12*(1 - k11)*x6 + (-1)*k18*k13*x5 + (-1)*k14*x5*x3)/k18),
  Eq(Derivative(x6, t), ((-1)*k18*k12*(1 - k11)*x6 + 1*k14*x5*x3 + (-1)*k18*k12*k11*x6 + (-1)*k18*k13*x6 + (-1)*k18*k15*x6)/k18),
  Eq(Derivative(x7, t), (1*k18*k12*k11*x6 + (-1)*k18*k13*x7 + (-1)*k18*k16*x7)/k18),
  Eq(Derivative(x8, t), ((-1)*k18*k10*x8 + 1*k18*k15*x6 + (-1)*k18*k13*x8)/k18) ]