Solve x^2 + 15x = - 50

x² + 15 x + 50 = 0 (rearrange by adding 50 to both sides)

(x + 10)(x + 5) = 0 (factorise the quadratic equation)

x + 10 = 0 or x + 5 = 0 (for the above to equal zero, at least one of the bracketed terms must equal zero)

x = -10 or x = -5 (solving the two equations that result from step 3)

The solution is x = -10, x = -5