Разложить на множители, 1)a^2-8ab+16b^2 2)81с^2-d^2+9c+d 3)ax^6-3x^6-ax^3+3x^3 4)25-m^2-12mn-36n^2

1) = a² - 2*4ab + (4b)² = (a-4b)²
2) = (9c-d)(9c+d) + (9c+d) = (9c+d) (9c-d+1)
3) = x∧6(a-3) - x³ (a-3) = (a-3) (x∧6 - x³) = x³ (a-3) (x³-1) = x³ (a-3) (x-1) (x²+x+1)
4) 5² - (m²+12nm +36n²) = 5² - (m+6n)² = (5 - m - 6n) (5 + m + 6n)