Question

Factorise $3x^2-x-4$.

Answer 1

Factorise the polynomial

$$\begin{gathered} 3x^2-x-4 \\ =3x^2-4x+3x-4 \\ =x(3x-4)+1(3x-4) \\ =(x+1)(3x-4) \end{gathered}$$

Hence, the factors of $3x^2-x-4$ are $(x+1)$and $(3x-4)$.