(7x2 – 4x + 8) – (4x2 + x – 5) = 7x2 – 4x + 8 – 4x2 – x + 5 = (7x2 – 4x2) + (– 4x – x) + (8 + 5) = 3x2 – 5x + 13
Ответ: 3x2 – 5x + 13