[ Eq(Derivative(x1, t), 0),
  Eq(Derivative(x2, t), (2*k12*(k9*k14/(k14 + k10*(1 + k15/k11))*k1 + k9*k14/(k14 + k10*(1 + k15/k11))*k13 - Abs(k9*k14/(k14 + k10*(1 + k15/k11))*k1 - k9*k14/(k14 + k10*(1 + k15/k11))*k13))/2 + 3/2*k12*21/100*k15/k11/(k14/k10)*(k9*k14/(k14 + k10*(1 + k15/k11))*k1 + k9*k14/(k14 + k10*(1 + k15/k11))*k13 - Abs(k9*k14/(k14 + k10*(1 + k15/k11))*k1 - k9*k14/(k14 + k10*(1 + k15/k11))*k13))/2 + (-1)*k12*x2/k2*x3/k3*k9*k1)/k12),
  Eq(Derivative(x3, t), ((-2)*k12*(k9*k14/(k14 + k10*(1 + k15/k11))*k1 + k9*k14/(k14 + k10*(1 + k15/k11))*k13 - Abs(k9*k14/(k14 + k10*(1 + k15/k11))*k1 - k9*k14/(k14 + k10*(1 + k15/k11))*k13))/2 + (-2)*k12*21/100*k15/k11/(k14/k10)*(k9*k14/(k14 + k10*(1 + k15/k11))*k1 + k9*k14/(k14 + k10*(1 + k15/k11))*k13 - Abs(k9*k14/(k14 + k10*(1 + k15/k11))*k1 - k9*k14/(k14 + k10*(1 + k15/k11))*k13))/2 + 1*k12*(Abs(1/2*(1 - k4)*k5 + 467) - Abs(1/2*(1 - k4)*k5 - 467))/2/65/2*x6/k3)/k12),
  Eq(Derivative(x4, t), 0),
  Eq(Derivative(x5, t), 0) ]