Your answer is x = -2 or x = -8
To solve x² + 10x + 16 = 0, we can factorise the expression.
First we find factors of 16:
1 and 16
2 and 8
4 and 4
Then we see which of these could add together to make our x-coefficient, which is 10. Here, the answer is 2 and 8.
Therefore the final factorisation is
(x + 2)(x + 8) = 0
And if we set each bracket equal to 0 and solve, we get x = -2 or x = -8
I hope this helps!