[ Eq(Derivative(x1, t), ((-1)*k25*(k2*x1*x2 - k3*x3) + 1*k25*k7*x7**2 + (-1)*k25*(k18*x1 - k18*x13))/k25),
  Eq(Derivative(x2, t), ((-1)*k25*(k2*x1*x2 - k3*x3) + 1*k25*k5*x5*x4 + (-1)*k25*k6*x2*x7)/k25),
  Eq(Derivative(x3, t), (1*k25*(k2*x1*x2 - k3*x3) + (-1)*k25*k4*x3*x4 + 1*k25*k8*x19*x7)/k25),
  Eq(Derivative(x4, t), ((-1)*k25*k4*x3*x4 + (-1)*k25*k5*x5*x4 + (-1)*k25*(k19*x4 - k19*x18))/k25),
  Eq(Derivative(x5, t), (1*k25*k4*x3*x4 + (-1)*k25*k5*x5*x4)/k25),
  Eq(Derivative(x6, t), (1*k25*k4*x3*x4 + 1*k25*k5*x5*x4 + (-1)*k25*(k20*x6 - k20*x17))/k25),
  Eq(Derivative(x7, t), ((-1)*k25*k6*x2*x7 + (-2)*k25*k7*x7**2 + (-1)*k25*k8*x19*x7 + (-1)*k25*(k21*x7 - k21*x15) + 2*k25*k22*x10/k1*(1 + x10/k1)*x9/((k23 + (1 + x10/k1)**2)*(k24 + x9)))/k25),
  Eq(Derivative(x8, t), (-2)*k25*k7*x7**2/k25),
  Eq(Derivative(x9, t), (1*k25*k7*x7**2 + 1*k25*k8*x19*x7 + (-1)*k25*(k17*x9 - k17*x11) + (-2)*k25*k22*x10/k1*(1 + x10/k1)*x9/((k23 + (1 + x10/k1)**2)*(k24 + x9)))/k25),
  Eq(Derivative(x10, t), ((-1)*k26*k9*x10*x11 + (-1)*k26*k12*x17*x10 + 1*k26*k14 + (-1)*k25*k22*x10/k1*(1 + x10/k1)*x9/((k23 + (1 + x10/k1)**2)*(k24 + x9)))/k26),
  Eq(Derivative(x11, t), ((-1)*k26*k9*x10*x11 + (-1)*k26*k10*x14*x11 + 1*k26*k11*x15**2 + 1*k26*k15 + (-1)*k26*k16*x11 + 1*k25*(k17*x9 - k17*x11))/k26),
  Eq(Derivative(x12, t), (1*k26*k9*x10*x11 + 1*k26*k10*x14*x11 + 1*k25*k22*x10/k1*(1 + x10/k1)*x9/((k23 + (1 + x10/k1)**2)*(k24 + x9)))/k26),
  Eq(Derivative(x13, t), (1*k26*k9*x10*x11 + 1*k26*k11*x15**2 + 1*k25*(k18*x1 - k18*x13))/k26),
  Eq(Derivative(x14, t), ((-1)*k26*k10*x14*x11 + 1*k26*k12*x17*x10 + (-2)*k26*k13*x14**2)/k26),
  Eq(Derivative(x15, t), (1*k26*k10*x14*x11 + (-2)*k26*k11*x15**2 + 1*k25*(k21*x7 - k21*x15))/k26),
  Eq(Derivative(x16, t), (-2)*k26*k11*x15**2/k26),
  Eq(Derivative(x17, t), ((-1)*k26*k12*x17*x10 + 1*k25*(k20*x6 - k20*x17))/k26),
  Eq(Derivative(x18, t), (1*k26*k12*x17*x10 + 1*k25*(k19*x4 - k19*x18))/k26),
  Eq(Derivative(x19, t), (1*k25*k6*x2*x7 + (-1)*k25*k8*x19*x7)/k25),
  Eq(Derivative(x20, t), 1*k26*k13*x14**2/k26) ]