Question

Find the product:
(x³ − 2x² + 5) × (4x − 1)

Answer 1

By horizontal method:

$$\begin{gathered} (x^3-2x^2+5)\times (4x-1) \\ =4x(x^3-2x^2+5)-1(x^3-2x^2+5) \\ =4x^4-8x^3+20x-x^3+2x^2-5 \\ =4x^4-9x^3+2x^2+20x-5 \end{gathered}$$