# How do you simplify -sqrt(144)?

The negative is really -1 times the square root, so do the square root first, multiply by -1 and get
$\left(- 1\right) \left(12\right) = - 12$

#### Explanation:

$- \sqrt{144}$

The negative sign is really a $- 1$ multiplying the square root, so let's write the expression this way:

$\left(- 1\right) \left(\sqrt{144}\right)$

We can now take the square root of 144:

$\left(- 1\right) \left(12\right) = - 12$

I think this question hinged on the fact that "you can't take the square root of a negative number" (which in a higher level class you will learn that you can). A question with the negative in the square root would look like this:

$\sqrt{- 144}$

And just for fun let's show what you do in this case:

$\sqrt{- 144} = \sqrt{144} \sqrt{- 1} = 12 \sqrt{- 1}$

And in that advanced class you will learn that $\sqrt{- 1} = i$, so the answer becomes

$\sqrt{- 144} = \sqrt{144} \sqrt{- 1} = 12 \sqrt{- 1} = 12 i$