[ Eq(Derivative(x1, t), (-1)*k1*(k2*x1*x10 - k3*x2)/k1),
  Eq(Derivative(x2, t), (1*k1*(k2*x1*x10 - k3*x2) + (-1)*k1*(k4*x2*x4 - k5*x3) + 1*k1*k10*x7)/k1),
  Eq(Derivative(x3, t), (1*k1*(k4*x2*x4 - k5*x3) + (-1)*k1*(k6*x3 - k7*x6*x5))/k1),
  Eq(Derivative(x4, t), ((-1)*k1*(k4*x2*x4 - k5*x3) + 1*k1*k11*x9)/k1),
  Eq(Derivative(x5, t), (1*k1*(k6*x3 - k7*x6*x5) + (-1)*k1*(k8*x5*x8 - k9*x7))/k1),
  Eq(Derivative(x6, t), 1*k1*(k6*x3 - k7*x6*x5)/k1),
  Eq(Derivative(x7, t), (1*k1*(k8*x5*x8 - k9*x7) + (-1)*k1*k10*x7)/k1),
  Eq(Derivative(x8, t), (-1)*k1*(k8*x5*x8 - k9*x7)/k1),
  Eq(Derivative(x9, t), (1*k1*k10*x7 + (-1)*k1*k11*x9)/k1),
  Eq(Derivative(x10, t), (-1)*k1*(k2*x1*x10 - k3*x2)/k1) ]