Solve the equation x²+4x−5=0

We need to find two numbers that multiply to -5 and add to 4. These numbers are 5 and -1.

$$(x + 5)(x - 1) = 0$$

$$x + 5 = 0 \quad \text{or} \quad x - 1 = 0$$ $$x = -5 \quad \text{or} \quad x = 1$$

The solutions are:
$x_1 = -5$
$x_2 = 1$