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