1. а) (4-x)2x = 8x - 2x^2
б) (x+y-xy)xy = x^2y + xy^2 - x^2y^2
в) (x+2)(4-x) = 4x - x^2 + 8 - 2x = 2x - x^2 + 8
2. (a+4)(2-a^2) - (3a+4)(4-a) = 2a - a^3 + 8 - 4a^2 - 12a + 3a^2 - 16 + 4a =
-a^3 - a^2 - 6a - 8 = -8 - 4 - 12 - 8 = -32
3. (4x-3)(2-x)=(3-2x)(3+2x)
8x - 4x^2 - 6 + 3x = 9 + 6x - 6x - 4x^2
11x - 4x^2 - 6 = 9 - 4x^2
11x + 3 = 0
11x = -3
x = -3/11