Question

(a + b)^2 -2(a + b)(a - b) + (a - b)^2 = 4b^2​

Answer 1

x² - 2xy + y² = (x - y)²

x = a + b

y = a - b

(a + b)^2 -2(a + b)(a - b) + (a - b)^2 = (a + b - (a - b))² = (a + b - a + b)² = (2b)² = 4b² доказано