Question

Find the product:
(x² − 5x + 8) × (x² + 2x − 3)

Answer 1

By horizontal method:

$$\begin{gathered} (x^2-5x+8)\times (x^2+2x-3) \\ =x^2(x^2-5x+8)+2x(x^2-5x+8)-3(x^2-5x+8) \\ =x^4-5x^3+8x^2+2x^3-10x^2+16x-3x^2+15x-24 \\ =x^4-3x^3-5x^2+31x-24 \end{gathered}$$