# How do you find all the zeros of F(x)=x^2+10x+25?

Apr 9, 2016

$x = - 5$

#### Explanation:

Factorise the equation into

$\left(x + a\right) \left(x + b\right)$

where $a + b = 10$ and $a \cdot b = 25$. Using trial and error, this should give you $a = 5$ and $b = 5$.

$\left(x + 5\right) \left(x + 5\right) = {\left(x + 5\right)}^{2}$

In order for this to be zero (i.e. to find the zeroes), $x + 5$ must be zero, so

$x + 5 = 0$
$x = - 5$