[ Eq(Derivative(x1, t), (1*k25*k1*x1*(1 - x1/k2) + (-1)*k25*1/(x4 + k3)*(k4*x2 + k5*x3)*x1/(x1 + k6))/k25),
  Eq(Derivative(x2, t), (1*k25*k7*x2*(1 - x2/k24) + 1*k25*k9*x5/(k10 + x5)*1/(x4 + k11) + (-1)*k25*k12*x1/(x1 + k13)*x2)/k25),
  Eq(Derivative(x3, t), (1*k25*k14*x1/(k15 + x4) + (-1)*k25*k16*x3 + (-1)*k25*k17*x1/(x1 + k18)*x3)/k25),
  Eq(Derivative(x4, t), (1*k25*k19 + 1*k25*k20*x1 + (-1)*k25*k21*x4)/k25),
  Eq(Derivative(x5, t), (1*k25*k22*x3 + (-1)*k25*k23*x5)/k25) ]