# If the slope of a line is 2 and the y-intercept is 4, what is the x-intercept?

##### 1 Answer
Mar 25, 2018

$\text{x-intercept } = - 2$

#### Explanation:

$\text{the equation of a line in "color(blue)"slope-intercept form}$ is.

•color(white)(x)y=mx+b

$\text{where m is the slope and b the y-intercept}$

$\text{here "m=2" and } b = 4$

$\Rightarrow y = 2 x + 4 \leftarrow \textcolor{b l u e}{\text{is the equation of the line}}$

$\text{When the line crosses the x-axis the corresponding}$
$\text{y-coordinate is zero. Substituting y = 0 into the}$
$\text{equation gives the x-intercept}$

$y = 0 \Rightarrow 2 x + 4 = 0 \Rightarrow x = - 2 \leftarrow \textcolor{red}{\text{x-intercept}}$
graph{(y-2x-4)((x+2)^2+(y-0)^2-0.04)((x-0)^2+(y-4)^2-0.04)=0 [-10, 10, -5, 5]}