[tex]A = (x+7)^{2} - 4 = (x+7)^{2} - 2^{2} = (x+7 + 2 )(x+7 - 2) = (x+9)(x+5)\\\\B = 49 - (2x-9)^{2} = 7^{2} - (2x-9)^{2} = (7 + 2x-9 ) (7-2x+9) = (2x -2)(16-2x)\\\\E = (3x+7)^{2} - (x-9)^{2} = (3x+7+x-9)(3x+7-x+9) = (4x-2)(2x+16)\\\\F = (5x+2)^{2} -(10x-3)^{2} = (5x+2+ 10x-3)(5x+2 - 10x+3) = (15x-1)(5-5x)[/tex]
