[ Eq(Derivative(x1, t), ((-1)*k1*(k2*x2*x1 - k3*x3) + 1*k1*(k5*x4 - k6*x5*x1) + (-1)*k1*(k9*x1*x7 - k10*x8))/k1),
  Eq(Derivative(x2, t), ((-1)*k1*(k2*x2*x1 - k3*x3) + 1*k1*(k15*x3*x7 - k16*x2*x9))/k1),
  Eq(Derivative(x3, t), (1*k1*(k2*x2*x1 - k3*x3) + (-1)*k1*k4*x3 + (-1)*k1*(k15*x3*x7 - k16*x2*x9))/k1),
  Eq(Derivative(x4, t), (1*k1*k4*x3 + (-1)*k1*(k5*x4 - k6*x5*x1) + (-1)*k1*(k11*x4*x6 - k12*x9))/k1),
  Eq(Derivative(x5, t), (1*k1*(k5*x4 - k6*x5*x1) + (-1)*k1*(k7*x5*x6 - k8*x7))/k1),
  Eq(Derivative(x6, t), ((-1)*k1*(k7*x5*x6 - k8*x7) + (-1)*k1*(k11*x4*x6 - k12*x9))/k1),
  Eq(Derivative(x7, t), (1*k1*(k7*x5*x6 - k8*x7) + (-1)*k1*(k9*x1*x7 - k10*x8) + (-1)*k1*(k15*x3*x7 - k16*x2*x9))/k1),
  Eq(Derivative(x8, t), (1*k1*(k9*x1*x7 - k10*x8) + 1*k1*(k13*x9 - k14*x8))/k1),
  Eq(Derivative(x9, t), (1*k1*(k11*x4*x6 - k12*x9) + (-1)*k1*(k13*x9 - k14*x8) + 1*k1*(k15*x3*x7 - k16*x2*x9))/k1) ]