Find the roots of the equation: x² − 5x + 6 = 0

We need two numbers that multiply to $-6$ and add to $-5$.
These are $-6$ and 1.

$$x^2 - 5x - 6 = (x - 6)(x + 1) = 0$$

$$x - 6 = 0 \quad \Rightarrow \quad x = 6$$ $$x + 1 = 0 \quad \Rightarrow \quad x = -1$$

x = 6,\ -1