Solve r=2A/b

$$r = \frac { 2 A } { b }$$

Solve for A

$$A=\frac{br}{2}$$

$$b\neq 0$$

Steps for Solving Linear Equation

Multiply both sides of the equation by b.

$$rb=2A$$

Swap sides so that all variable terms are on the left hand side.

$$2A=rb$$

The equation is in standard form.

$$2A=br$$

Divide both sides by 2.

$$\frac{2A}{2}=\frac{br}{2}$$

Dividing by 2 undoes the multiplication by 2.

$$A=\frac{br}{2}$$

Solve for b

$$\left\{\begin{matrix}b=\frac{2A}{r}\text{, }&A\neq 0\text{ and }r\neq 0\\b\neq 0\text{, }&r=0\text{ and }A=0\end{matrix}\right.$$

Steps for Solving Linear Equation

Variable b cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by b.

$$rb=2A$$

Divide both sides by r.

$$\frac{rb}{r}=\frac{2A}{r}$$

Dividing by r undoes the multiplication by r.

$$b=\frac{2A}{r}$$

Variable b cannot be equal to 0.

$$b=\frac{2A}{r}\text{, }b\neq 0$$