-4x^3+21x^2-23x+6 / (x-4)
\(\frac{-4x^3+21x^2-23x+6}{x-4} = \frac{(-4 x^{2} +5x-3)(x-4)-6}{x-4}\)
-4x² + 5x - 3x - 4|-4x³ + 21x² - 23x + 6 -(-4x³ + 16x²) 5x² - 23x -(-5x² - 20x) -3x + 6 -(-3x + 12) -6