Answered

The equation of line LM is [tex]5x - y = -4[/tex]. What is the equation of a line perpendicular to line LM in slope-intercept form that contains the point [tex]\((-3, 2)\)[/tex]?

A. [tex]y = 5x + 13[/tex]
B. [tex]y = -\frac{1}{5}x + \frac{7}{5}[/tex]
C. [tex]y = -\frac{1}{5}x - \frac{7}{5}[/tex]
D. [tex]y = 5x - 17[/tex]



Answer :

To find the equation of a line perpendicular to the given line [tex]\(5x - y = -4\)[/tex] and containing the point [tex]\((-3, 2)\)[/tex], we follow these steps:

1. Find the slope of line LM:

The given equation of line LM is [tex]\(5x - y = -4\)[/tex].

To find the slope, we convert the equation to the slope-intercept form [tex]\(y = mx + b\)[/tex]:
[tex]\[ 5x - y = -4 \implies y = 5x + 4 \][/tex]
Here, [tex]\(m = 5\)[/tex] is the slope of line LM.

2. Determine the slope of the perpendicular line:

The slope of a line perpendicular to another line is the negative reciprocal of the original slope.

For the slope [tex]\(m = 5\)[/tex], the negative reciprocal is [tex]\(-\frac{1}{5}\)[/tex].

3. Use point-slope form to find the equation:

We know the line passes through the point [tex]\((-3, 2)\)[/tex] and has a slope of [tex]\(-\frac{1}{5}\)[/tex].

The point-slope form of a line's equation is:
[tex]\[ y - y_1 = m(x - x_1) \][/tex]
Plug in the point [tex]\((-3, 2)\)[/tex] and the slope [tex]\(-\frac{1}{5}\)[/tex]:
[tex]\[ y - 2 = -\frac{1}{5}(x + 3) \][/tex]

4. Convert to slope-intercept form:

Expand and simplify to put the equation in the form [tex]\(y = mx + b\)[/tex]:
[tex]\[ y - 2 = -\frac{1}{5}(x + 3) \][/tex]
[tex]\[ y - 2 = -\frac{1}{5}x - \frac{3}{5} \][/tex]
[tex]\[ y = -\frac{1}{5}x - \frac{3}{5} + 2 \][/tex]
Convert 2 to a fraction with a common denominator (5):
[tex]\[ y = -\frac{1}{5}x - \frac{3}{5} + \frac{10}{5} \][/tex]
Combine the fractions:
[tex]\[ y = -\frac{1}{5}x + \frac{7}{5} \][/tex]

So, the equation of the line is:
[tex]\[ y = -\frac{1}{5}x + \frac{7}{5} \][/tex]

Thus, the correct answer is [tex]\(\boxed{y = -\frac{1}{5}x + \frac{7}{5}}\)[/tex].