Solve pi=2pir/d

$$\pi = \frac { 2 \pi r } { d }$$

Solve for d

$$d=2r$$

$$r\neq 0$$

Solution Steps

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

$$\pi d=2\pi r$$

Cancel out \pi on both sides.

$$d=2r$$

Variable d cannot be equal to 0.

$$d=2r\text{, }d\neq 0$$

Solve for r

$$r=\frac{d}{2}$$

$$d\neq 0$$

Steps for Solving Linear Equation

Multiply both sides of the equation by d.

$$\pi d=2\pi r$$

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

$$2\pi r=\pi d$$

Cancel out \pi on both sides.

$$2r=d$$

Divide both sides by 2.

$$\frac{2r}{2}=\frac{d}{2}$$

Dividing by 2 undoes the multiplication by 2.

$$r=\frac{d}{2}$$