Question

Factorise:
x² – 11x – 80

Answer 1

$$\begin{gathered} x^2-11x-80 \\ =x^2-16x+5x-80 \\ =x\left(x-16\right)+5\left(x-16\right) \\ =\left(x-16\right)\left(x+5\right) \end{gathered}$$