{ diff(x1, t) = ((-2)*k15*(1/2*k2*x1^2 - k1*x2) + (-1)*k15*(k7*x1*x3 - k5*x5))/k15,
  diff(x2, t) = 1*k15*(1/2*k2*x1^2 - k1*x2)/k15,
  diff(x3, t) = ((-2)*k15*(1/2*k4*x3^2 - k3*x4) + (-1)*k15*(k7*x1*x3 - k5*x5))/k15,
  diff(x4, t) = (1*k15*(1/2*k4*x3^2 - k3*x4) + (-1)*k15*k11*x4*x8 + 1*k15*k14*x10)/k15,
  diff(x5, t) = (1*k15*(k7*x1*x3 - k5*x5) + (-1)*k15*k10*x5*x8 + 1*k15*k13*x9)/k15,
  diff(x6, t) = (-2)*k15*(1/2*k8*x6^2 - k6*x7)/k15,
  diff(x7, t) = (1*k15*(1/2*k8*x6^2 - k6*x7) + (-1)*k15*(k9*x7 - k12*x8))/k15,
  diff(x8, t) = 1*k15*(k9*x7 - k12*x8)/k15,
  diff(x9, t) = (1*k15*k10*x5*x8 + (-1)*k15*k13*x9)/k15,
  diff(x10, t) = (1*k15*k11*x4*x8 + (-1)*k15*k14*x10)/k15 }