[ Eq(Derivative(x1, t), ((-1)*k10*k1*x4*x1/k2/(1 + x1/k2 + x2/k4) + 1*k10*k7*x5*x2/k8/(1 + x3/k6 + x2/k8 + x1/k9))/k10),
  Eq(Derivative(x2, t), (1*k10*k1*x4*x1/k2/(1 + x1/k2 + x2/k4) + (-1)*k10*k3*x4*x2/k4/(1 + x1/k2 + x2/k4) + 1*k10*k5*x5*x3/k6/(1 + x3/k6 + x2/k8 + x1/k9) + (-1)*k10*k7*x5*x2/k8/(1 + x3/k6 + x2/k8 + x1/k9))/k10),
  Eq(Derivative(x3, t), (1*k10*k3*x4*x2/k4/(1 + x1/k2 + x2/k4) + (-1)*k10*k5*x5*x3/k6/(1 + x3/k6 + x2/k8 + x1/k9))/k10),
  Eq(Derivative(x4, t), 0/k10),
  Eq(Derivative(x5, t), 0/k10) ]