contestada

A line has this equation: y=-3x+7
Write an equation for the parallel line that goes through (-4,-8)

Respuesta :

Given:

The equation of line is [tex]y=-3x+7[/tex].

A line is parallel to given equation and passes through the point (-4,-8).

To find:

The equation of parallel line.

Solution:

The equation of a line is

[tex]y=-3x+7[/tex]

On comparing this equation with [tex]y=mx+b[/tex], we get

[tex]m=-3[/tex]

So, slope of given line is -3.

We know that, slopes of parallel lines are equal. It means, the slope of the parallel line is also -3.

The parallel line passes through (-4,-8) and having slope -3. So, the equation of line is

[tex]y-y_1=m(x-x_1)[/tex]

[tex]y-(-8)=(-3)(x-(-4))[/tex]

[tex]y+8=(-3)(x+4)[/tex]

[tex]y+8=-3x-12[/tex]

[tex]y=-3x-12-8[/tex]

[tex]y=-3x-20[/tex]

Therefore, the equation of parallel line is [tex]y=-3x-20[/tex].