(x²+1)(x-4)+2a = x³-3x²+bx+14

jawab

(x²+1)(x - 4) + 2a = x³ - 3x² +6x + 14

x³ - 4x² + x - 4 + 2a  = x³ - 3x² + 6x + 14

2a = x³ - x³ + 4x² - 3x² - x +6x + 4 +14
2a = x² + 5x + 18
x = 1/2 (x² + 5x + 18)