[ Eq(Derivative(x1, t), (1*k19*k1/k19 + 1*k19*k2*x2**k3/(k4**k3 + x2**k3)/k19 + (-1)*k19*k5*x1)/k19),
  Eq(Derivative(x2, t), (1*k19*k13*x5 + (-1)*k19*k15*x4*x2 + 1*k19*k14*x5 + 1*k19*k16*x5 + 1*k19*k17*x5/(k11 + x3 + 2*x4 + 2*x5)/k19)/k19),
  Eq(Derivative(x3, t), (1*k19*k6*x1 + (-1)*k19*k7*x3 + (-2)*k19*k8*x3**2 + 2*k19*k9*x4 + (-1)*k19*k10*x3/(k11 + x3 + 2*x4 + 2*x5)/k19 + (-1)*k19*k12*x3)/k19),
  Eq(Derivative(x4, t), (1*k19*k8*x3**2 + (-1)*k19*k9*x4 + 1*k19*k13*x5 + (-1)*k19*k14*x4 + (-1)*k19*k15*x4*x2 + (-1)*k19*k17*x4/(k11 + x3 + 2*x4 + 2*x5)/k19 + (-1)*k19*k12*x4)/k19),
  Eq(Derivative(x5, t), ((-1)*k19*k13*x5 + 1*k19*k15*x4*x2 + (-1)*k19*k14*x5 + (-1)*k19*k16*x5 + (-1)*k19*k17*x5/(k11 + x3 + 2*x4 + 2*x5)/k19)/k19) ]