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Find the equation of the line in slope-intercept form that passes through the following points. Simplify your answer.

(−5,−8) and (−7,8)

Respuesta :

slope intercept form: y = -8

Answer:

y=-8(x+6)

Step-by-step explanation:

The equation of a line is [tex]y=mx+b[/tex] where m is the pending and b is the y intercept,

First we are going to calculate m:

If you have two points [tex]A=(x_{1},y_{1})\\B=(x_{2},y_{2})[/tex],

[tex]m=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex]

In this case we have A=(-5,-8) and B=(-7,8)

[tex]x_1=-5, y_1=-8\\x_2=-7,y_2=8[/tex]

Replacing in the formula:

[tex]m=\frac{8-(-8)}{(-7)-(-5)}\\\\m=\frac{16}{-2} \\\\m=-8[/tex]

Then [tex]y=-8x+b[/tex].

We have to find b, we can find it replacing either of the points in [tex]y=-8x+b[/tex]:

Replacing the point (-5,-8):

[tex]y=-8x+b\\-8=-8.(-5)+b\\-8=40+b\\-8-40=b\\-48=b[/tex]

Or replacing the point (-7,8):

[tex]y=-8x+b\\8=-8.(-7)+b\\8=56+b\\8-56=b\\-48=b[/tex]

The answer is the same with both points.

Then we have:

y=-8x-48

y=-8(x+6)