Precalculus Examples

$x + 3 y = 12$

Step 1

Subtract $3 y$ from both sides of the equation.

$x = 12 - 3 y$

Step 2

To rewrite as a function of $y$ , write the equation so that $x$ is by itself on one side of the equal sign and an expression involving only $y$ is on the other side.

$f (y) = 12 - 3 y$