# How do you solve v^2+ 10v - 21 = 0 by completing the square?

$y = {v}^{2} + 10. v - 21 = 0$
$y = {v}^{2} + 10 v + 25 - 25 - 21 = 0$
$v + 5 = s q r 46 \to v = - 5 + s q r 46$
$v + 5 = - s q r 46 \to v = - 5 - s q r 46$