Chapter 2: Problem 120
Find the slope of the line \(3 x-9 y=7\).
Short Answer
Expert verified
The slope is \(\frac{1}{3}\).
Step by step solution
01
Rewrite the equation in slope-intercept form
The slope-intercept form of a line's equation is given by \[ y = mx + b \]. To convert the given equation \( 3x - 9y = 7 \) into this form, solve for \( y \).
02
Isolate the term with y
Subtract \( 3x \) from both sides to isolate terms involving \( y \) on one side: \[ -9y = -3x + 7 \].
03
Divide by the coefficient of y
Divide every term by \( -9 \) to solve for \( y \): \[ y = \frac{-3x + 7}{-9} \].
04
Simplify the equation
Rewrite the equation by simplifying the fractions: \[ y = \frac{1}{3} x - \frac{7}{9} \].
05
Identify the slope
In the slope-intercept form \( y = mx + b \), \( m \) represents the slope. Hence, the slope \( m \) is \( \frac{1}{3} \).
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Slope-Intercept Form
The slope-intercept form is a way of writing linear equations. This form makes it easy to identify the slope and the y-intercept of a line.
The general formula is given by: \( y = mx + b \). Here, \( m \) represents the slope of the line, and \( b \) represents the y-intercept, which is where the line crosses the y-axis.
For the equation \( 3x - 9y = 7 \), we need to rewrite it in slope-intercept form to easily find the slope. This involves isolating the y variable on one side of the equation. Once we have \( y \) by itself, we can clearly see the values of \( m \) and \( b \).
Converting an equation to slope-intercept form simplifies solving problems involving the slope and graphing the line.
The general formula is given by: \( y = mx + b \). Here, \( m \) represents the slope of the line, and \( b \) represents the y-intercept, which is where the line crosses the y-axis.
For the equation \( 3x - 9y = 7 \), we need to rewrite it in slope-intercept form to easily find the slope. This involves isolating the y variable on one side of the equation. Once we have \( y \) by itself, we can clearly see the values of \( m \) and \( b \).
Converting an equation to slope-intercept form simplifies solving problems involving the slope and graphing the line.
Linear Equations
Linear equations represent straight lines on a graph. They are equations in which the highest power of the variable is one.
These equations are generally written in the form: \(Ax + By = C \) where \(A, B, \) and \(C \) are constants.
In the given example, \(3x - 9y = 7\), it's a standard form of a linear equation.
These equations are generally written in the form: \(Ax + By = C \) where \(A, B, \) and \(C \) are constants.
In the given example, \(3x - 9y = 7\), it's a standard form of a linear equation.
- We can manipulate this equation to get it into slope-intercept form, which allows us to identify the slope and y-intercept more easily.
- This process involves solving for y.
Solving for y
Solving for y means to isolate y on one side of the equation, so it reads \(y = \) some expression.
Here's how you can solve for y in the given equation \(3x - 9y = 7 \):
Solving for y transforms the equation into a more useful form for analyzing and graphing the line.
Here's how you can solve for y in the given equation \(3x - 9y = 7 \):
- First, subtract \(3x \) from both sides to get \(-9y = -3x + 7 \).
- Next, divide every term by \(-9 \) to isolate y, resulting in \ y = \frac{-3x + 7}{-9} \.
- Lastly, simplify the equation to get \( y = \frac{1}{3} x - \frac{7}{9} \).
Solving for y transforms the equation into a more useful form for analyzing and graphing the line.