{ 1*k1*x1 + 1*k1*x2 = k1*k26,
  1*k1*x3 + 1*k1*x4 + 1*k1*x5 = k1*k27,
  1*k1*x6 + 1*k1*x7 + 1*k1*x8 = k1*k28 }