Chapter 11: Problem 222
Find the slope, the \(\mathrm{y}\) -intercept, and the \(\mathrm{x}\) -intercept of the equation \(2 x-3 y-18=0\)
Short Answer
Expert verified
The slope of the equation is \(m = \frac{2}{3}\), the y-intercept is \(b = -6\), and the x-intercept is \(x = 9\).
Step by step solution
01
Rewrite the equation in slope-intercept form (y = mx + b)
To write the given equation in slope-intercept form (y = mx + b), we need to first move the 3y term to the other side and then divide each term by 3:
\(2x - 3y - 18 = 0\)
Add 3y to both sides and get:
\(2x - 18 = 3y\)
Now divide each term by 3:
\(y = \frac{2}{3}x - 6\)
02
Determine the slope and y-intercept
In the equation we obtained in Step 1, the slope (m) is the coefficient of the x term, and the y-intercept (b) is the constant term. From the equation:
\(y = \frac{2}{3}x - 6\)
The slope (m) is:
\(m = \frac{2}{3}\)
The y-intercept (b) is:
\(b = -6\)
03
Determine the x-intercept
To find the x-intercept, we set the value of y to 0 and solve for x:
\(\frac{2}{3}x - 6 = 0\)
Add 6 to both sides:
\(\frac{2}{3}x = 6\)
Now multiply both sides by \(\frac{3}{2}\) to solve for x:
\(x = \frac{3}{2} \cdot 6\)
\(x = 9\)
The x-intercept is 9.
So, the slope of the equation is \(\frac{2}{3}\), the y-intercept is -6, and the x-intercept is 9.
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Linear Equations
A linear equation is an equation that creates a straight line when graphed on a coordinate plane. These equations are generally presented in different forms, such as the standard form, slope-intercept form, or point-slope form.
In this context, we are interested in the slope-intercept form, which is represented as \(y = mx + b\). Here:
One of the main benefits of understanding linear equations is their simplicity and reliability in predicting and explaining relationships between variables.
In this context, we are interested in the slope-intercept form, which is represented as \(y = mx + b\). Here:
- \(m\) is the slope of the line.
- \(b\) is the y-intercept, which is the point where the line crosses the y-axis.
One of the main benefits of understanding linear equations is their simplicity and reliability in predicting and explaining relationships between variables.
X-Intercept
The x-intercept of a line is a point where the line crosses the x-axis. This is found by setting the y-value of the linear equation to zero and solving for x.
In simple terms, it tells us the value of x when y is zero, helping us understand where the line "hits" the horizontal axis on a graph.
For example, in our equation \(\frac{2}{3}x - 6 = 0\), we calculated the x-intercept by:
In simple terms, it tells us the value of x when y is zero, helping us understand where the line "hits" the horizontal axis on a graph.
For example, in our equation \(\frac{2}{3}x - 6 = 0\), we calculated the x-intercept by:
- Adding 6 to both sides, resulting in \(\frac{2}{3}x = 6\).
- Multiplying both sides by \(\frac{3}{2}\), leading us to \(x = 9\).
Y-Intercept
The y-intercept of a line is the point where the line crosses the y-axis. This is determined by setting the x-value of the linear equation to zero and solving for y, but in the slope-intercept form \(y = mx + b\), the y-intercept is directly given by the constant term \(b\).
This intercept represents the value of y when x is zero.
In the equation \(y = \frac{2}{3}x - 6\), we can see that the y-intercept is -6, meaning the line crosses the y-axis at the point (0, -6).
This intercept represents the value of y when x is zero.
In the equation \(y = \frac{2}{3}x - 6\), we can see that the y-intercept is -6, meaning the line crosses the y-axis at the point (0, -6).
- This information is useful because it gives us a starting point for graphing the line.
- Knowing the y-intercept helps in understanding the initial value or starting point in real-world scenarios modeled by linear equations.
Slope of a Line
The slope of a line is a number that describes both the direction and the steepness of the line. It is represented by the letter \(m\) in the slope-intercept equation \(y = mx + b\).
The slope is defined as the ratio of the change in y to the change in x between two points on the line.
In our example equation, \(y = \frac{2}{3}x - 6\), the slope is \(\frac{2}{3}\). This slope tells us that for every 3 units the line moves horizontally (right), it moves 2 units vertically (up).
The slope is defined as the ratio of the change in y to the change in x between two points on the line.
In our example equation, \(y = \frac{2}{3}x - 6\), the slope is \(\frac{2}{3}\). This slope tells us that for every 3 units the line moves horizontally (right), it moves 2 units vertically (up).
- A positive slope indicates that the line goes upwards as it moves from left to right.
- A negative slope would mean the line slopes downwards.
- If the slope is zero, the line would be horizontal, indicating no vertical change as it moves.