(a-5)(11-b) = 11a - ab - 55 + 5b
(-8-a)(b+2) = -8b - 2a - ab - 2
(-7-b)(a-7) = -7a + 49 + 7b - ab
(x-4)(x+8) = x^2 + 8x - 4x - 32 = x^2 + 4x - 32
(x-5)(9-x) = 9x - x^2 - 45 + 5x = -x^2 + 14x - 45
(8+3x)(2y-1) = 16y - 8 + 6xy - 3x
(2a-1)(3a+7) = 6a^2 + 14a - 3a - 7 = 6a^2 + 11a - 7
(3a-2b)(2a-3b) = 6a^2 - 9ab - 4ab + 6b^2 = 6a^2 - 13ab + 6b^2
(15a+27)(-5a-9) = -75a^2 - 135a - 135a - 243 = -75a^2 - 270a - 243
(a-5)(11-b) = 11a - ab - 55 + 5b
(-8-a)(b+2) = -8b - 2a - ab - 2
(-7-b)(a-7) = -7a + 49 + 7b - ab
(x-4)(x+8) = x^2 + 8x - 4x - 32 = x^2 + 4x - 32
(x-5)(9-x) = 9x - x^2 - 45 + 5x = -x^2 + 14x - 45
(8+3x)(2y-1) = 16y - 8 + 6xy - 3x
(2a-1)(3a+7) = 6a^2 + 14a - 3a - 7 = 6a^2 + 11a - 7
(3a-2b)(2a-3b) = 6a^2 - 9ab - 4ab + 6b^2 = 6a^2 - 13ab + 6b^2
(15a+27)(-5a-9) = -75a^2 - 135a - 135a - 243 = -75a^2 - 270a - 243