What is the standard form equation of the line shown below? Graph of a line going through negative 2, 3 and 1, negative 3

1. y + 3 = −2(x − 1)
2. y = −2x − 1
3. 2x + y = −1
4. −2x − y = 1

What is the standard form equation of the line shown below Graph of a line going through negative 2 3 and 1 negative 3 1 y 3 2x 1 2 y 2x 1 3 2x y 1 4 2x y 1 class=

Respuesta :

Answer:

3. 2x + y = −1

Step-by-step explanation:

To find the equation of the line, we write it first in the slope-intercept form:

[tex]y=mx+q[/tex]

where

m is the slope

q is the y-intercept

From the graph, we see that the line crosses the y-axis at y = -1, so the y-intercept is -1:

[tex]q=-1[/tex]

Now we have to find the slope, by calculating the rate of change of the line through 2 points:

[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]

Taking the two points at (-2,3) and (1,-3), we find:

[tex]m=\frac{-3-3}{1-(-2)}=\frac{-6}{3}=-2[/tex]

So the equation of the line is

[tex]y=-2x-1[/tex]

Now we have to re-arrange it in the standard form, so in the form

[tex]ax+bx=c[/tex]

where a, b and c are integer numbers.

To do that, we simply add +2x on both sides of the equation of the line in the slope-intercept form, and we get:

[tex]y+2x=-1[/tex]

So, option 3).