Chapter 3: Problem 13
Find the \(x\) -intercept and the \(y\) -intercept for the graph of each equation. $$ x-y=8 $$
Short Answer
Expert verified
x-intercept: (8,0), y-intercept: (0,-8)
Step by step solution
01
Find the x-intercept
Set y to 0 in the equation and solve for x. The x-intercept is where the graph crosses the x-axis.
02
Step 1.1: Substitute y=0
Substitute 0 for y in the equation: x - 0 = 8
03
Step 1.2: Solve for x
Simplify the equation to find x: x = 8
04
Find the y-intercept
Set x to 0 in the equation and solve for y. The y-intercept is where the graph crosses the y-axis.
05
Step 2.1: Substitute x=0
Substitute 0 for x in the equation: 0 - y = 8
06
Step 2.2: Solve for y
Simplify the equation to find y: -y = 8 *y = -8*
07
Conclusion: Identify the intercepts
The x-intercept is where the graph crosses the x-axis, and the y-intercept is where it crosses the y-axis. Using the previous steps: x-intercept: (8,0) y-intercept: (0,-8)
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
x-intercept
In algebra, the x-intercept of a graph is the point where it crosses the x-axis. To find the x-intercept, we set the value of y to 0 and solve for x.
For example, let's look at the equation given in the exercise:
\(x - y = 8\)
Step 1: Set y to 0.
This transforms the equation to:
\(x - 0 = 8\)
Step 2: Solve for x.
This simplifies to:
\(x = 8\)
Hence, the x-intercept is the point (8, 0). This means the graph crosses the x-axis at the coordinate (8, 0).
Understanding this helps us know where the graph begins horizontally when plotting points.
For example, let's look at the equation given in the exercise:
\(x - y = 8\)
Step 1: Set y to 0.
This transforms the equation to:
\(x - 0 = 8\)
Step 2: Solve for x.
This simplifies to:
\(x = 8\)
Hence, the x-intercept is the point (8, 0). This means the graph crosses the x-axis at the coordinate (8, 0).
Understanding this helps us know where the graph begins horizontally when plotting points.
y-intercept
The y-intercept of a graph is the point where it crosses the y-axis. To find the y-intercept, we set the value of x to 0 and solve for y.
Using the same equation:
\(x - y = 8\)
Step 1: Set x to 0.
Doing so changes the equation to:
\(0 - y = 8\)
Step 2: Solve for y.
We get:
\(-y = 8\)
Divide by -1:
\(y = -8\)
Therefore, the y-intercept is the point (0, -8). This indicates that the graph crosses the y-axis at the coordinate (0, -8).
This understanding lets us know where the graph starts vertically.
Using the same equation:
\(x - y = 8\)
Step 1: Set x to 0.
Doing so changes the equation to:
\(0 - y = 8\)
Step 2: Solve for y.
We get:
\(-y = 8\)
Divide by -1:
\(y = -8\)
Therefore, the y-intercept is the point (0, -8). This indicates that the graph crosses the y-axis at the coordinate (0, -8).
This understanding lets us know where the graph starts vertically.
solving equations
Solving equations is a fundamental part of finding intercepts. It involves finding the variable's value that makes the equation true.
Here are the basic steps we follow to solve for a variable:
For instance, substituting y=0 in the equation \(x - y = 8\) simplifies to \(x = 8\). Similarly, substituting x=0 simplifies to solving \(-y = 8\), which gives us y = -8.
Knowing how to solve equations helps reveal graph intersections clearly and is a valuable tool for various math problems beyond just finding intercepts.
Here are the basic steps we follow to solve for a variable:
- Substitute any known values: In our intercept problems, we substitute either x=0 or y=0.
- Simplify the equation: This often means performing basic arithmetic operations.
- Isolate the variable: Do this by getting the variable by itself on one side of the equation.
For instance, substituting y=0 in the equation \(x - y = 8\) simplifies to \(x = 8\). Similarly, substituting x=0 simplifies to solving \(-y = 8\), which gives us y = -8.
Knowing how to solve equations helps reveal graph intersections clearly and is a valuable tool for various math problems beyond just finding intercepts.