Chapter 3: Problem 5
Graph each linear equation. \(-3 x+2 y=3\)
Short Answer
Expert verified
Convert to slope-intercept form, plot the y-intercept, use the slope to find another point, and draw the line.
Step by step solution
01
Convert to Slope-Intercept Form
First, we need to convert the given linear equation into the slope-intercept form, which is \( y = mx + b \), where \( m \) is the slope and \( b \) is the y-intercept. Start with the given equation \(-3x + 2y = 3\). Add \( 3x \) to both sides to get \(2y = 3x + 3\). Then, divide every term by 2 to isolate \( y \): \[ y = \frac{3}{2}x + \frac{3}{2} \]
02
Identify Slope and Y-Intercept
In the slope-intercept form \( y = \frac{3}{2}x + \frac{3}{2} \), the slope \( m = \frac{3}{2} \) and the y-intercept \( b = \frac{3}{2} \) are easily identifiable. This tells us the line rises 3 units for every 2 units it runs horizontally and crosses the y-axis at \( y = \frac{3}{2} \).
03
Plot the Y-Intercept
On a graph, plot the y-intercept \( \left(0, \frac{3}{2} \right) \). This is where the line crosses the y-axis.
04
Use the Slope to Find Another Point
From the y-intercept, use the slope \( \frac{3}{2} \) to find another point. Starting at \( \left(0, \frac{3}{2} \right) \), move up 3 units and 2 units to the right to arrive at the point \( (2, 3 + \frac{3}{2}) = (2, \frac{9}{2}) \) or approximately \( (2, 4.5) \), if plotting by estimation is acceptable.
05
Draw the Line
With the points \( \left(0, \frac{3}{2} \right) \) and \( (2, \frac{9}{2}) \), draw a straight line through these points, extending the line across the grid to complete the graph of the equation.
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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 of a linear equation is a very convenient way to represent a line graphically. It is characterized by the equation format \( y = mx + b \). Here, \( m \) represents the slope, and \( b \) denotes the y-intercept—the point where the line crosses the y-axis.
To convert any linear equation into this form, algebraic manipulation is necessary. You start by isolating \( y \) on one side of the equation. In our example, the equation \(-3x + 2y = 3\) was manipulated by first adding \(3x\) to both sides to get \(2y = 3x + 3\). Dividing all terms by 2 gave us the slope-intercept form \( y = \frac{3}{2}x + \frac{3}{2} \).
This format makes it easier to identify both the slope and the y-intercept, which are crucial for graphing the equation on a coordinate plane.
To convert any linear equation into this form, algebraic manipulation is necessary. You start by isolating \( y \) on one side of the equation. In our example, the equation \(-3x + 2y = 3\) was manipulated by first adding \(3x\) to both sides to get \(2y = 3x + 3\). Dividing all terms by 2 gave us the slope-intercept form \( y = \frac{3}{2}x + \frac{3}{2} \).
This format makes it easier to identify both the slope and the y-intercept, which are crucial for graphing the equation on a coordinate plane.
Slope and Y-Intercept
Understanding the slope and y-intercept is key to graphing linear equations efficiently. The slope \( m \) of a line reflects how steep it is, describing the vertical change per unit of horizontal change. For example, a slope of \( \frac{3}{2} \) means the line rises 3 units vertically for every 2 units it moves horizontally.
The y-intercept \( b \) is where the line crosses the y-axis. This point is easy to spot because it occurs where \( x = 0 \). In our case, \( b = \frac{3}{2} \), so the line meets the y-axis at \( (0, \frac{3}{2}) \).
With the slope and y-intercept clearly identified from the equation \( y = \frac{3}{2}x + \frac{3}{2} \), it becomes straightforward to draw an accurate representation of the line on the graph.
The y-intercept \( b \) is where the line crosses the y-axis. This point is easy to spot because it occurs where \( x = 0 \). In our case, \( b = \frac{3}{2} \), so the line meets the y-axis at \( (0, \frac{3}{2}) \).
With the slope and y-intercept clearly identified from the equation \( y = \frac{3}{2}x + \frac{3}{2} \), it becomes straightforward to draw an accurate representation of the line on the graph.
Plotting Points
Plotting points is essentially setting the foundation for drawing the line of a linear equation. It starts with marking the y-intercept, which serves as the initial point. In this example, the y-intercept of \( (0, \frac{3}{2}) \) is plotted first. This makes it a starting reference point for the line.
Next, use the slope \( \frac{3}{2} \) to find additional points. From the y-intercept, move vertically 3 units up and 2 units to the right, landing on \( (2, \frac{9}{2}) \). This is another point through which the line will pass.
With these two points established, drawing a straight line through them will give you the graph of the linear equation. The line can then be extended across the graph for a clearer view of the relationship described by the equation. This method of plotting ensures accuracy and provides a visual insight into the equation's linear nature.
Next, use the slope \( \frac{3}{2} \) to find additional points. From the y-intercept, move vertically 3 units up and 2 units to the right, landing on \( (2, \frac{9}{2}) \). This is another point through which the line will pass.
With these two points established, drawing a straight line through them will give you the graph of the linear equation. The line can then be extended across the graph for a clearer view of the relationship described by the equation. This method of plotting ensures accuracy and provides a visual insight into the equation's linear nature.