Преобразуйте в многочлен: a) 4x(2x-1) - (x-3)(x + 3); б) (p + 3)(p – 11) + (p + 6)²; в) 7(a + b)² - 14ab.

a) 4x(2x-1) - (x-3)(x + 3) = 8x^2 - 4x - (x^2 - 9) = 8x^2 - 4x - x^2 + 9 = 7x^2 - 4x + 9 б) (p + 3)(p – 11) + (p + 6)² = p^2 - 11p + 3p - 33 + p^2 + 12p + 36 = 2p^2 + 4p + 3 = 2p^2 + 4p + 3 в) 7(a + b)² - 14ab = 7(a^2 + 2ab + b^2) - 14ab = 7a^2 + 14ab + 7b^2 - 14ab = 7a^2 + 7b^2