(x-y)^2-(m+n)^2(m-2n)^2-(2p-3q)^2(2a-3c)^2-(4d+5d)^29 (m+n)^2-(m-n)^24 (a-b)^2-(a+b)^216 (a+b)^2-9 (x-y)^2 ! ​

(a + 2b)² - (3c + 4d)² = (a + 2b - 3c - 4d)(a + 2b + 3c + 4d);

(m - 2n)² - (2p - 3q)² = (m - 2n - (2p - 3q))(m - 2n + 2p - 3q) = (m - 2n - 2p + 3q)(m - 2n + 2p - 3q);

9(m + n)² - (m - n)² = (3(m + n))² - (m - n)² = (3(m + n) - (m - n))(3(m + n) + m - n) = (3m + 3n - m + n)(3m + 3n + m - n) = (2m + 4n)(4m + 2n) = 2(m + 2n) · 2(2m + n) = 4(m + 2n)(2m + n);

16(a + b)² - 9(x + y)² = (4(a + b))² - (3(x + y))² = (4a + 4b - (3x + 3y))(4a + 4b + 3x + 3y) = (4a + 4b - 3x - 3y)(4a + 4b + 3x + 3y).

Решил не всё :(