Solve for w w^2-9=0

$w^{2} - 9 = 0$

Add $9$ to both sides of the equation.

$w^{2} = 9$

Take the square root of both sides of the equation to eliminate the exponent on the left side.

$w = \pm \sqrt{9}$

Simplify $\pm \sqrt{9}$ .

Rewrite $9$ as $3^{2}$ .

$w = \pm \sqrt{3^{2}}$

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

$w = \pm 3$

The complete solution is the result of both the positive and negative portions of the solution.

First, use the positive value of the $\pm$ to find the first solution.

$w = 3$

Next, use the negative value of the $\pm$ to find the second solution.

$w = - 3$

The complete solution is the result of both the positive and negative portions of the solution.

$w = 3, - 3$