[ Eq(Derivative(x1, t), ((-1)*k11*k1*x1 + 1*k11*k7*x7 + 1*k11*k10*x8*k13)/k11),
  Eq(Derivative(x2, t), (1*k11*k1*x1 + (-1)*k11*k2*x2*k13 + 1*k11*k9*x8)/k11),
  Eq(Derivative(x3, t), (1*k11*k2*x2*k13 + (-1)*k11*k3*x3)/k11),
  Eq(Derivative(x4, t), (1*k11*k3*x3 + (-1)*k11*k4*x4)/k11),
  Eq(Derivative(x5, t), (1*k11*k4*x4 + (-1)*k11*k5*x5*k13)/k11),
  Eq(Derivative(x6, t), (1*k11*k5*x5*k13 + (-1)*k11*k6*x6)/k11),
  Eq(Derivative(x7, t), (1*k11*k6*x6 + (-1)*k11*k7*x7 + (-1)*k11*k8*x7)/k11),
  Eq(Derivative(x8, t), (1*k11*k8*x7 + (-1)*k11*k9*x8 + (-1)*k11*k10*x8*k13)/k11),
  Eq(Derivative(x9, t), 0),
  Eq(Derivative(x10, t), 0),
  Eq(Derivative(x11, t), 0),
  Eq(Derivative(x12, t), 0),
  Eq(Derivative(x13, t), 0),
  Eq(Derivative(x14, t), 0) ]