Solve 21=b/a

$$21 = \frac { b } { a }$$

Solve for a

$$a=\frac{b}{21}$$

$$b\neq 0$$

Steps for Solving Linear Equation

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

$$21a=b$$

Divide both sides by 21.

$$\frac{21a}{21}=\frac{b}{21}$$

Dividing by 21 undoes the multiplication by 21.

$$a=\frac{b}{21}$$

Variable a cannot be equal to 0.

$$a=\frac{b}{21}\text{, }a\neq 0$$

Solve for b

$$b=21a$$

$$a\neq 0$$

Solution Steps

Multiply both sides of the equation by a.

$$21a=b$$

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

$$b=21a$$