# How do you simplify sqrt441?

Apr 11, 2016

$\sqrt{441} = 21$

#### Explanation:

Using the fact that for $x \in \mathbb{R}$ we have $\sqrt{{x}^{2}} = | x |$:

$\sqrt{441} = \sqrt{{21}^{2}} = | 21 | = 21$

Apr 11, 2016

21

#### Explanation:

Let's have a look at some of the factors of 441:
$9 \cdot 49 = 441$
$147 \cdot 3 = 441$
and (among others) $21 \cdot 21 = 441$

Recall that a square number is a number multiplied by itself once.
We can then say that ${21}^{2}$ ( referred to as 21 squared) is equal to 441. Additionally:

$\sqrt{{21}^{2}} = \sqrt{441}$

Again, recall that:

$\sqrt{{n}^{2}} = n$

Therefore, we can rewrite our above problem as:

$21 = \sqrt{441}$

Therefore: 21.