A line contains the points [tex]\((8,9)\)[/tex] and [tex]\((-12,-7)\)[/tex]. Using point-slope form, write the equation of the line that is parallel to the given line and passes through [tex]\((-5,-15)\)[/tex].

A. [tex]\(y - 15 = -\frac{5}{4}(x - 5)\)[/tex]
B. [tex]\(y + 15 = -\frac{5}{4}(x + 5)\)[/tex]
C. [tex]\(y + 5 = \frac{4}{5}(x + 15)\)[/tex]
D. [tex]\(y + 15 = \frac{4}{5}(x + 5)\)[/tex]

Please select the best answer from the choices provided.



Answer :

To find the equation of a line that is parallel to a given line and passes through a specific point, we need to follow these steps:

1. Calculate the slope of the given line:

The given points are [tex]\((8,9)\)[/tex] and [tex]\((-12,-7)\)[/tex].

The formula to find the slope between two points [tex]\((x_1, y_1)\)[/tex] and [tex]\((x_2, y_2)\)[/tex] is:
[tex]\[ \text{slope} = \frac{y_2 - y_1}{x_2 - x_1} \][/tex]

Plugging in the coordinates:
[tex]\[ \text{slope} = \frac{-7 - 9}{-12 - 8} = \frac{-16}{-20} = \frac{4}{5} \][/tex]

2. Understand that parallel lines have the same slope:

The line we need to find is parallel to the above line, so it also has a slope of [tex]\(\frac{4}{5}\)[/tex].

3. Use the point-slope form to write the equation of the parallel line:

The point-slope form is:
[tex]\[ y - y_1 = m(x - x_1) \][/tex]

where [tex]\(m\)[/tex] is the slope and [tex]\((x_1, y_1)\)[/tex] is the point through which the line passes. Here, the point through which the parallel line passes is [tex]\((-5, -15)\)[/tex].

Substituting the slope [tex]\( \frac{4}{5} \)[/tex] and the point [tex]\((-5, -15)\)[/tex] into the point-slope form:
[tex]\[ y - (-15) = \frac{4}{5}(x - (-5)) \][/tex]
Simplifying this:
[tex]\[ y + 15 = \frac{4}{5}(x + 5) \][/tex]

So, after deriving the equation in the proper form, the correct choice is:

D. [tex]\(y + 15 = \frac{4}{5}(x + 5)\)[/tex]