Problem 62

Question

a. Rewrite the given equation in slope-intercept form. b. Give the slope and \(y\) -intercept. c. Use the slope and y-intercept to graph the linear function. $$4 x+6 y+12=0$$

Step-by-Step Solution

Verified
Answer
The slope-intercept form of the given equation is \(y = -2/3x - 2\), with slope -2/3 and y-intercept -2.
1Step 1: Rewrite in slope-intercept form
The given equation is \(4x + 6y + 12 = 0\). We can rearrange this equation to solve for y: \[\[-(4x) - 12\] on both sides of the equation to isolate 'y'. This gives us \(y = \[-(4/6)x -12/6\], simplifying further gives us \(y = -2/3x - 2\]. So, the equation in slope-intercept form is \(y = -2/3x - 2\).
2Step 2: Identifying Slope and Y-Intercept
In the slope-intercept form of the linear equation \(y = mx + b\), 'm' is the slope and 'b' is the y-intercept. Thus, in the rewritten equation \(y = -2/3x - 2\), the slope 'm' is -2/3 and the y-intercept 'b' is -2.
3Step 3: Graphing the Linear Function
The y-intercept is -2. This is where the line crosses the y-axis. So, start by plotting a dot at that point (-2) on the y-axis. The slope of the line is -2/3, which means for each positive step along the x-axis, we go two steps down, and for each negative step along the x-axis, we go two steps up. Draw the line passing through these points.

Key Concepts

Slope-Intercept FormLinear FunctionY-intercept
Slope-Intercept Form
The slope-intercept form is an equation of a straight line and is perhaps the most convenient form for graphing linear equations. It is written as y = mx + b, where m represents the slope of the line and b represents the y-intercept, which is the point where the line crosses the y-axis.

To convert a linear equation to slope-intercept form, you need to solve for y so that it is isolated on one side of the equation. For the given problem, starting from 4x + 6y + 12 = 0, we subtract 4x and 12 from both sides to get 6y = -4x - 12. Next, we divide each term by 6 to solve for y, resulting in y = -2/3x - 2, which is now in slope-intercept form.
Linear Function
A linear function is a function whose graph is a straight line. Linear functions are described by linear equations, which relate two variables in such a way that if plotted on a Cartesian plane, they would form a line. These equations can always be written in the form of y = mx + b, where each variable and coefficient represents a fundamental characteristic of the line.

For instance, in our exercise y = -2/3x - 2, the linear function indicates a constant rate of change of y with respect to x. This constant rate is the slope -2/3, which means that for every unit increase in x, y decreases by 2/3 units, demonstrating a consistent, linear relationship between the two variables.
Y-intercept
The y-intercept is the point where the graph of a function or an equation crosses the y-axis. It is a significant feature in graphing because it provides a starting point for drawing the graph of the equation. The y-intercept is represented by the b in the slope-intercept equation y = mx + b.

In the provided problem, the y-intercept is -2. This means that when x is 0, y is -2. When graphing, you would begin by placing a point at (0, -2) on the graph. You would then use the slope to determine the direction and steepness of the line, ensuring your graph accurately represents the linear relationship depicted by the equation.