# What is the y-intercept of the line given by the equation y=9/2x - 4?

May 9, 2017

$- 4$

#### Explanation:

Given equation: $y = \frac{9}{2} x - 4$
The given equation of the line is in slope-intercept form. The general slope-intercept form would be:
$y = m x + b$ where $m$ is the slope and $b$ is the y-intercept of the line

Therefore, the slope of the given equation is $\frac{9}{2}$ and the y-intercept is $- 4$.

May 9, 2017

(0,-4)

#### Explanation:

graph{9/2x-4 [-4.98, 5.02, -4.76, 0.24]}

Method 1

The graph of $y = \frac{9}{2} x - 4$ is shown above.

From the graph, it is shown that the coordinates of the y-intercept is $\left(0 , - 4\right)$. Although this is not needed, the coordinates of the x-intercept is $\left(\frac{8}{9} , 0\right)$.

Method 2

From the above coordinates, you can see that at the y-intercept, the value of $x = 0$. Conversely, at the x-intercept, the value of $y = 0$.

Thus, when $x = 0$,
$y = \left(\frac{9}{4}\right) \cdot 0 - 4$
$y = - 4$
$\therefore$ y-intercept is $\left(0 , - 4\right)$

Be careful of leaving your answer simply as $y = - 4$.

The correct form of answering should be leaving it as (0,-4).