# How do you find the x intercept of 4x-12=0 ?

Aug 21, 2017

Replace $y$ with $0$ (if there is a $y$), then solve for $x$. The $x$-intercept is at $x = 3$.

#### Explanation:

The equation $4 x - 12 = 0$ is for a vertical line, since (the non-existent) $y$ does not depend on $x$. We can solve this for $x$ as follows:

$4 x - 12 = 0$
$4 x \textcolor{w h i t e}{-} \textcolor{w h i t e}{12} = 12$
$\textcolor{w h i t e}{4} x \textcolor{w h i t e}{-} \textcolor{w h i t e}{12} = 3$

Meaning, for any $y$ we choose, we will always get $x = 3$. And since the $x$-intercept occurs where $y = 0$, we know that value of $y$ will also give us $x = 3$. Thus, our intercept is at $x = 3$.

Here is a graph of the line $4 x - 12 = 0$:

graph{4x-12=0.0000001y [-10, 10, -5, 5]}