Хелп, мои мозги замкнуло (u+5v)2−(5u+v)2 заранее

(u + 5v)² - (5u + v)² = [(u + 5v) - (5u + v)][(u + 5v) + (5u + v)] =
= (u + 5v - 5u - v)(u + 5v + 5u + v) = (4v - 4u)(6v + 6u) =
= 4 * 6 * (v - u)(v + u) = 24(v² - u²)

(u + 5v)^2 - (5u + v)^2 = (u + 5v + 5u + v)*(u + 5v - 5u - v) = (6u + 6v)*(4v - 4u) = 24(u+v)(v-u) = 24(v^2-u^2)