Simplify - square root of -144

$- \sqrt{- 144}$

Step 1

Rewrite $- 144$ as $- 1 (144)$ .

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

Step 2

Rewrite $\sqrt{- 1 (144)}$ as $\sqrt{- 1} \cdot \sqrt{144}$ .

$- (\sqrt{- 1} \cdot \sqrt{144})$

Step 3

Rewrite $\sqrt{- 1}$ as $i$ .

$- (i \cdot \sqrt{144})$

Step 4

Rewrite $144$ as $12^{2}$ .

$- (i \cdot \sqrt{12^{2}})$

Step 5

Pull terms out from under the radical, assuming positive real numbers.

$- (i \cdot 12)$

Step 6

Move $12$ to the left of $i$ .

$- (12 \cdot i)$

Step 7

Multiply $12$ by $- 1$ .

$- 12 i$