Автор - slavkalog766
(y + x)² = y² + 2xy + x²
(a - 3)² = a² - 6a + 9
2(2y + a)² = 2(4y² + 4ya + a²) = 8y² + 8ya + 2a²
(5a + 2b)² = 25a² + 20ab + 4b²
(8x - y)² + 16 xy = 64x² - 16xy + y² + 16xy = 64x² + y²
(y - 8)(y + 8) = y² - 64
(3x - 2)(3x + 2) = 9x² - 4
(6x + 5y)(5y - 6x) = (6x + 5y)(-(6x - 5y)) = (-(6x + 5y)(6x - 5y)) = -(36x² - 25y²) = 25y² - 36x²