Solve for b 4a^2-b^2=0

$4 a^{2} - b^{2} = 0$

Subtract $4 a^{2}$ from both sides of the equation.

$- b^{2} = - 4 a^{2}$

Divide each term in $- b^{2} = - 4 a^{2}$ by $- 1$ and simplify.

Divide each term in $- b^{2} = - 4 a^{2}$ by $- 1$ .

$\frac{- b^{2}}{- 1} = \frac{- 4 a^{2}}{- 1}$

Simplify the left side.

Dividing two negative values results in a positive value.

$\frac{b^{2}}{1} = \frac{- 4 a^{2}}{- 1}$

Divide $b^{2}$ by $1$ .

$b^{2} = \frac{- 4 a^{2}}{- 1}$

Simplify the right side.

Move the negative one from the denominator of $\frac{- 4 a^{2}}{- 1}$ .

$b^{2} = - 1 \cdot (- 4 a^{2})$

Rewrite $- 1 \cdot (- 4 a^{2})$ as $- (- 4 a^{2})$ .

$b^{2} = - (- 4 a^{2})$

Multiply $- 4$ by $- 1$ .

$b^{2} = 4 a^{2}$

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

$b = \pm \sqrt{4 a^{2}}$

Simplify $\pm \sqrt{4 a^{2}}$ .

Rewrite $4 a^{2}$ as ${(2 a)}^{2}$ .

$b = \pm \sqrt{{(2 a)}^{2}}$

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

$b = \pm 2 a$

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.

$b = 2 a$

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

$b = - 2 a$

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

$b = 2 a$

$b = - 2 a$

$b = 2 a$

$b = - 2 a$