Find the quadratic polynomial if the roots are 4 and 5.

• ক $x^2 + 7x + 20$
• খ $x^2 + 9x + 20$
• গ $x^2 - 9x - 20$
• ঘ $x^2 - 9x + 20$ ✅ সঠিক উত্তর