Choose the equation that represents the graph below:
Graph of a line passing through points negative 2,0 and 0,-4

y = -2x - 4
y = 2x + 4
y = -2x + 4
y = 2x - 4

Question

Choose the equation that represents the graph below:
Graph of a line passing through points negative 2,0 and 0,-4

y = -2x - 4 
y = 2x + 4 
y = -2x + 4 
y = 2x - 4

anonymous · Answer

@iGreen

igreen · Answer

All of those options are in the form of $y = mx + b$, where $m$ is the slope, and $b$ is the y-intercept.

We have to find out which one passes through the points (-2, 0) and (0, -4).

(0, -4) tells us that the y-intercept is -4.

So that means that our equation has to have -4 at the end of it.

$y = mx - 4$ is what we have so far.

igreen · Answer

Okay, now lets find the slope between the two points by plugging them into the slope formula.

$m = \dfrac{y_2-y_1}{x_2-x_1}$

$m = \dfrac{-4-0}{~~~0+2}$

Add & Subtract:

$m = \dfrac{-4}{~~~2}$

Can you divide -4 / 2?

anonymous · Answer

-2

igreen · Answer

Yep!

So that gives us $y = -2x - 4$.