Problem 24

Question

Determine the equation of the line that satisfies the stated requirements. Put the equation in standard form. The line with slope 1 and \(x\) -intercept ( 2,0 )

Step-by-Step Solution

Verified
Answer
The equation in standard form is \( x - y = 2 \).
1Step 1: Identify the slope and x-intercept
The problem states that the line has a slope of 1 and passes through the x-intercept (2, 0). We need this information to write the equation of the line.
2Step 2: Use the Point-Slope Form of a Line
The point-slope form of a linear 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. Plug in \( m = 1 \), \( x_1 = 2 \), and \( y_1 = 0 \). This gives us \( y - 0 = 1(x - 2) \) or \( y = x - 2 \).
3Step 3: Convert to Standard Form
Standard form of a line is \( Ax + By = C \), where \( A \), \( B \), and \( C \) are integers, and \( A \) should be positive. Starting from \( y = x - 2 \), we can rearrange it to \( -x + y = -2 \). Adding \( x \) to both sides, we get \( x - y = 2 \).
4Step 4: Ensure Integers in Standard Form
Ensure that the coefficients are integers and that the leading coefficient \( A \) is positive. Here, the equation \( x - y = 2 \) already satisfies the condition for standard form, with \( A = 1 \), \( B = -1 \), and \( C = 2 \).

Key Concepts

Slope-Intercept FormPoint-Slope FormStandard Form
Slope-Intercept Form
The slope-intercept form is a common way to write the equation of a line. This format is particularly useful because it clearly shows the slope and y-intercept of the line. The general formula is \( y = mx + b \), where \( m \) is the slope and \( b \) is the y-intercept.

When you know the slope of a line and where it crosses the y-axis, you can immediately write the equation in this form. For example, if a line has a slope of 1 and crosses the y-axis at -2, the equation is \( y = 1x - 2 \) or simply \( y = x - 2 \).

This form is particularly useful for quickly graphing a line or understanding how the line behaves with changes in \( x \). The value \( m \) shows how steep the line is, and positive values mean the line ascends to the right, while negative values descend.
Point-Slope Form
Point-slope form is beneficial when you know the slope of a line and one point through which it passes. The formula for point-slope form is \( y - y_1 = m(x - x_1) \). Here, \((x_1, y_1)\) is a point on the line, and \( m \) is the slope.

This form is especially handy when you don't have the y-intercept but know another point instead. For instance, given a slope of 1 and an x-intercept of (2, 0), you could directly use point-slope form: \( y - 0 = 1(x - 2) \). Simplifying this gives you \( y = x - 2 \).

Point-slope form provides insight into how the line changes with x while anchoring it to a known point. It's a flexible form that can be converted to slope-intercept form if needed, as well as directly employed to find other line characteristics.
Standard Form
The standard form of a line equation is another way to express linear equations. The general equation is \( Ax + By = C \), where \( A \), \( B \), and \( C \) are integers, and \( A \) should be positive.

To convert equations from slope-intercept or point-slope to standard form, rearrange the terms to fit \( Ax + By = C \). From the earlier steps, if we start with \( y = x - 2 \), moving the terms gives \( -x + y = -2 \). Making \( A \) positive by adding \( x \) to both sides results in \( x - y = 2 \), which is in standard form.

The standard form is particularly useful in mathematical operations like systems of equations or when you need integer coefficients. It also gives a uniform representation that can be useful in both algebraic manipulations and analysis of line intersections.