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