Problem 58 - Algebra 1

Question

Write the equation in slope-intercept form. Then graph the equation. $$6 x+y=0$$

Step-by-Step Solution

Answer

The equation in slope-intercept form is \(y=-6x\). The line represented by this equation slopes downwards, with a y-intercept of 0.

Step 1: Convert the Equation to Slope-Intercept Form

The given equation is \(6x+y=0\). We can convert this into slope-intercept form by isolating \(y\). To accomplish this, subtract \(6x\) from both sides of the equation, giving \(y=-6x\). This is now in the slope-intercept form \(y=mx+b\), where the slope \(m\) is -6 and the y-intercept \(b\) is 0.

Step 2: Graph the Equation

Start by plotting the y-intercept, which in this case is \(0\). The slope is \(-6\), which is the same as \(-6/1\). This means for each step to the right on the x-axis, go down six steps. This will give a downward sloping line.

Key Concepts

Understanding Slope-Intercept Form

The slope-intercept form is a way of writing the equation of a straight line so that the slope (rate of change) and the y-intercept (the point where the line crosses the y-axis) are immediately apparent.

In mathematical terms, the slope-intercept form is represented as \( y = mx + b \), where:\( m \) stands for the slope of the line, and \( b \) represents the y-intercept.

Understanding this formula is crucial because it directly tells us two key pieces of information about a line on a graph. By easily identifying these values, we can quickly sketch the linear equation on a coordinate plane without needing to calculate additional points on the line.

The slope \( m \) is a measure of steepness or the inclination of the line. A positive slope means the line rises as it moves from left to right, while a negative slope indicates that the line falls. Furthermore, the y-intercept \( b \) indicates the point where the line crosses the y-axis, thereby providing a starting point for drawing the line.

Graphing Linear Equations

When it comes to graphing linear equations, having a solid grasp of the slope-intercept form aids in plotting these lines accurately.

Here's a simple guide to graphing linear equations:

• Begin by locating the y-intercept on the graph. It's the point \( (0, b) \) on the y-axis.
• From the y-intercept, use the slope to determine the direction and steepness of the line. The slope, written as a fraction \( \frac{rise}{run} \), tells us how many units to move up or down (rise) and to the right or left (run). If the slope is a whole number, it's assumed to have a denominator of 1.
• After using the slope to find a second point, you can draw a straight line through the two points, extending it across the graph. This line represents the set of all possible solutions to the linear equation.

By understanding the specifics of the slope and y-intercept, graphing becomes a much smoother process, and the line's behavior - whether it is increasing, decreasing, horizontal, or vertical - becomes predictable.

Solving for y in Linear Equations

Solving for y is an essential step in the process of converting linear equations into slope-intercept form and graphing them. This process involves manipulating the equation so that y is on one side and everything else on the other.

This can be done through a few algebraic steps:

• Move the x-terms to the opposite side of the equation by adding or subtracting them from both sides.
• If there are coefficients attached to y that are not 1, divide every term by that coefficient to isolate y.
• Make sure the equation is in the form \( y = mx + b \) to identify the slope and y-intercept easily.

If in the equation, the coefficient of y is 1, as in the exercise given \( 6x + y = 0 \), subtracting \( 6x \) from both sides immediately provides us with \( y \) on one side; which is the ideal form for graphing.