Write an equation of each line that passes through the following points in slope-intercept form:
A (8, –1) and B (–4, 17)

Respuesta :

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Answer:

[tex]\large\boxed{y=-\dfrac{3}{2}x+11}[/tex]

Step-by-step explanation:

The slope-intercept form of an equation of a line:

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

m - slope

b - y-intercept

The formula of a slope:

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

We have the point A(8, -1) and B(-4, 17). Substitute:

[tex]m=\dfrac{17-(-1)}{-4-8}=\dfrac{18}{-12}=-\dfrac{3}{2}[/tex]

The equation of a line:

[tex]y=-\dfrac{3}{2}x+b[/tex]

Put the coordinates of the point A(8, -1) to the equation of a line:

[tex]-1=-\dfrac{3}{2}(8)+b[/tex]

[tex]-1=-3(4)+b[/tex]

[tex]-1=-12+b[/tex]     add 12 to both sides

[tex]11=b\to b=11[/tex]

Finally we have the equation of a line in a slope-intercept form:

[tex]y=-\dfrac{3}{2}x+11[/tex]