[tex]\\ \sf\longmapsto 7x + 2y {}^{3} - 4xy + 3x - 2xy {}^{3} + 7xy + 2xy - 5x + {6y}^{3} \\ \\ \sf\longmapsto 2y {}^{3} + 6 {y}^{3} - 2xy {}^{3 } + 7x + 3x - 5x - 4xy + 7xy + 2xy \\ \\ \sf\longmapsto 8y {}^{3} - 2xy {}^{3} + 5x + 5xy \\ \\ \sf\longmapsto 2y {}^{3} (4 - x) + 5x(1 + y)[/tex]
