Get the information you need with the help of IDNLearn.com's expert community. Find the solutions you need quickly and accurately with help from our knowledgeable community.

Which line is perpendicular to [tex][tex]$y=\frac{4}{9} x-7$[/tex][/tex]?

[tex]\[
\begin{array}{ll}
A. \quad y=-\frac{4}{9} x+\frac{1}{5} & C. \quad y=-\frac{9}{4} x-\frac{1}{8} \\
B. \quad y=\frac{4}{9} x-\frac{1}{6} & D. \quad y=\frac{9}{4} x+\frac{1}{7}
\end{array}
\][/tex]


Sagot :

To determine which line is perpendicular to [tex]\( y = \frac{4}{9}x - 7 \)[/tex], we need to follow the steps below:

1. Determine the slope of the given line.
2. Find the slope of the line that would be perpendicular to it.
3. Identify which of the given lines has this slope.

### Step 1: Determine the slope of the given line.
The given line equation is:
[tex]\[ y = \frac{4}{9}x - 7 \][/tex]

The slope ([tex]\( m \)[/tex]) of the line [tex]\( y = mx + b \)[/tex] is the coefficient of [tex]\( x \)[/tex]. Therefore, the slope [tex]\( m \)[/tex] of the given line is:
[tex]\[ m = \frac{4}{9} \][/tex]

### Step 2: Find the slope of the perpendicular line.
The slope of any line perpendicular to another is the negative reciprocal of the slope of the original line. The negative reciprocal of [tex]\( \frac{4}{9} \)[/tex] is calculated as follows:

[tex]\[ m_{\text{perpendicular}} = -\frac{1}{\frac{4}{9}} = -\frac{9}{4} \][/tex]

### Step 3: Identify which of the given lines has this slope.
We need to check the slopes of the given lines to find the one with a slope of [tex]\( -\frac{9}{4} \)[/tex].

1. [tex]\( y = -\frac{4}{9}x + \frac{1}{5} \)[/tex]
Slope: [tex]\( -\frac{4}{9} \)[/tex]

2. [tex]\( y = \frac{4}{9}x - \frac{1}{6} \)[/tex]
Slope: [tex]\( \frac{4}{9} \)[/tex]

3. [tex]\( y = -\frac{9}{4}x - \frac{1}{8} \)[/tex]
Slope: [tex]\( -\frac{9}{4} \)[/tex]

4. [tex]\( y = \frac{9}{4}x + \frac{1}{7} \)[/tex]
Slope: [tex]\( \frac{9}{4} \)[/tex]

Comparing these slopes with [tex]\( -\frac{9}{4} \)[/tex], we find that the line:

[tex]\[ y = -\frac{9}{4}x - \frac{1}{8} \][/tex]

has the slope [tex]\( -\frac{9}{4} \)[/tex], which is the negative reciprocal of [tex]\( \frac{4}{9} \)[/tex].

Thus, the line perpendicular to [tex]\( y = \frac{4}{9}x - 7 \)[/tex] is:

[tex]\[ y = -\frac{9}{4}x - \frac{1}{8} \][/tex]

Therefore, the correct answer is:
[tex]\[ \boxed{y = -\frac{9}{4} x - \frac{1}{8}} \][/tex]