Question

find (3x-2y+4)(3x-2y-4)

Answer 1

$(3x - 2y + 4)(3x - 2y - 4) \\ = (3x - 2y) {}^{2} - (4) {}^{2} \\ = 9x {}^{2} - 12xy + 4y {}^{2} - 16$