(4a - b)(b + 4a) = 4ab + 4a4a - bb - b4a = 4ab + 16a^2 - b^2 - 4ab = 16a^2 - b^2(x^2 + 1)(x^2 - 1) = x^2*x^2 - x^2 + x^2 - 1 = x^4 - 1(a - 2)(a + 2) - 2a(5 - a) = a^2 - 4 - 10a + 2a^2 = 3a^2 - 10a - 4(y - 9)^2 - 3y(y + 1) = y^2 - 18y + 81 - 3y^2 - 3y = -2y^2 - 21y + 81

Разложение на множители:

c^2 - 0.25 = (c + 0.5)(c - 0.5)x^2 - 8x + 16 = (x - 4)^225x - x^3 = x(25 - x^2) = x(5 - x)(5 + x)x^2 - x - y^2 - y = (x - y)(x + y - 1)