What is the slope of a line that is perpendicular to the line whose equation is [tex]2x + 7y = 5[/tex]?

A. [tex]-\frac{7}{2}[/tex]
B. [tex]-\frac{7}{5}[/tex]
C. [tex]\frac{2}{7}[/tex]
D. [tex]\frac{7}{2}[/tex]



Answer :

To find the slope of a line that is perpendicular to the line given by the equation [tex]\(2x + 7y = 5\)[/tex], follow these steps:

1. Convert the given equation to slope-intercept form:
The slope-intercept form of a line's equation is [tex]\(y = mx + b\)[/tex], where [tex]\(m\)[/tex] is the slope.

Starting with the given equation:
[tex]\[ 2x + 7y = 5 \][/tex]

Solve for [tex]\(y\)[/tex]:

[tex]\[ 7y = -2x + 5 \][/tex]

[tex]\[ y = \left( -\frac{2}{7} \right)x + \frac{5}{7} \][/tex]

This equation is now in the form [tex]\(y = mx + b\)[/tex], where:
[tex]\[ m = -\frac{2}{7} \][/tex]

So, the slope [tex]\(m\)[/tex] of the original line is [tex]\(-\frac{2}{7}\)[/tex].

2. Find the slope of the perpendicular line:
The slope of a line perpendicular to another line is the negative reciprocal of the original slope. The negative reciprocal of [tex]\(m\)[/tex] is found by flipping the fraction and changing the sign.

The original slope is:
[tex]\[ m = -\frac{2}{7} \][/tex]

Therefore, the negative reciprocal is:
[tex]\[ \frac{7}{2} \][/tex]

3. Select the correct answer choice:
Among the given options, we determine that:

[tex]\[ \frac{7}{2} \][/tex]

matches the slope of the line perpendicular to the given line.

Thus, the correct answer is:

D. [tex]\(\frac{7}{2}\)[/tex]