Chapter 9: Problem 17
In Exercises \(7-24,\) find the general form of the equation of the line satisfying the conditions given and graph the line. With \(x\) -intercept \((-5,0)\) and slope 2
Short Answer
Expert verified
y = 2x + 10.
Step by step solution
01
Identify key information
The exercise provides the x-intercept of the line as (-5, 0) and the slope as 2.
02
Recall the point-slope form equation
The point-slope form of a line's equation is given by: y - y_1 = m(x - x_1), where m is the slope and (x_1, y_1) is a point on the line.
03
Substitute the given values
Using the point-slope form equation y - y_1 = m(x - x_1) with: m =2 and (x_1, y_1) = (-5, 0): y - 0 =2(x - (-5)).
04
Simplify the equation
Simplify the equation: y = 2(x + 5).
05
Convert to slope-intercept form
Distribute to obtain the equation in the slope-intercept form (y = mx + b): y = 2x + 10.
06
Graph the line
To graph the line, start at the x-intercept (-5, 0). Use the slope of 2 to find another point on the line: Move up 2 units and right 1 unit from (-5, 0) to get (-4, 2). Draw the line through these two points.
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.
x-intercept
The x-intercept is where a line crosses the x-axis. At this point, the value of y is always 0. For our example, the x-intercept is given as (-5, 0). This means when the line intersects the x-axis, the x-coordinate is -5.
To find the equation of the line with a known x-intercept and slope, you can use this point as one of the key components. Understanding the x-intercept is crucial because it helps to easily plot the graph and to convert between different forms of the linear equation.
To find the equation of the line with a known x-intercept and slope, you can use this point as one of the key components. Understanding the x-intercept is crucial because it helps to easily plot the graph and to convert between different forms of the linear equation.
point-slope form
The point-slope form of a line’s equation is particularly useful when you know one point on the line and the slope. It is written as: \( y - y_1 = m(x - x_1) \). Here, \((x_1, y_1)\) is a known point and m is the slope.
In our exercise: \((x_1, y_1) = (-5, 0)\) and m = 2.
Substituting these into the point-slope formula gives us: \( y - 0 = 2(x - (-5)) \), which simplifies to \( y = 2(x + 5) \).
This form is useful for quickly writing the equation of a line when you don't have the y-intercept readily available.
In our exercise: \((x_1, y_1) = (-5, 0)\) and m = 2.
Substituting these into the point-slope formula gives us: \( y - 0 = 2(x - (-5)) \), which simplifies to \( y = 2(x + 5) \).
This form is useful for quickly writing the equation of a line when you don't have the y-intercept readily available.
slope-intercept form
The slope-intercept form of a linear equation is one of the most common ways to express the equation of a line. It has the form: \( y = mx + b \), where m is the slope and b is the y-intercept.
From our simplified point-slope equation \( y = 2(x + 5) \), distributing 2 over \( (x+5) \) results in: \( y = 2x + 10 \).
Here, the slope m = 2 and the y-intercept b = 10. This form is great for quickly identifying the steepness and vertical position of a line.
From our simplified point-slope equation \( y = 2(x + 5) \), distributing 2 over \( (x+5) \) results in: \( y = 2x + 10 \).
Here, the slope m = 2 and the y-intercept b = 10. This form is great for quickly identifying the steepness and vertical position of a line.
graphing lines
Graphing a line requires understanding both the slope and intercepts of the line.
- Start by plotting the x-intercept, given in our case as (-5, 0).
- Then, using the slope, move vertically and horizontally to mark another point. With slope m = 2, for every 1 unit you move horizontally, you move 2 units vertically.
- From (-5, 0), moving up 2 units and right 1 unit lands us on the point (-4, 2).