307. Найдите разность многочленов: 1) x² + 8x и 4 – 3x; 2) 2x² + 5x и 4x² - 2x; 3) 4x²-7x+3 и х²- 8х + 11; 4) 9m² - 5m + 4 и -10m + m³ + 5.

1) $$ (x^2 + 8x) - (4 - 3x) = x^2 + 8x - 4 + 3x = x^2 + 11x - 4 $$ 2) $$ (2x^2 + 5x) - (4x^2 - 2x) = 2x^2 + 5x - 4x^2 + 2x = -2x^2 + 7x $$ 3) $$ (4x^2 - 7x + 3) - (x^2 - 8x + 11) = 4x^2 - 7x + 3 - x^2 + 8x - 11 = 3x^2 + x - 8 $$ 4) $$ (9m^2 - 5m + 4) - (-10m + m^3 + 5) = 9m^2 - 5m + 4 + 10m - m^3 - 5 = -m^3 + 9m^2 + 5m - 1 $$