[tex]2a - 4xy - 2y {}^{2} = 2 \times (x + y) {}^{2} - 5x + 6 - 4xy - 2y {}^{2} = 2(x {}^{2} + 2xy + y {}^{2} ) - 5x - 24xy - 2y {}^{2} = 2x {}^{2} + 4xy + 2y {}^{2} - 5x - 24xy - 2y {}^{2} = 2x {}^{2} - 20xy - 5x[/tex]
