Linear Functions Practice Problems y=mx+b - Slope & Y-Intercept

Master linear functions with practice problems covering slope, y-intercept, graphing, and real-world applications. Build confidence with step-by-step solutions.

📚What You'll Master in Linear Functions Practice
  • Identify slope (m) and y-intercept (b) from linear equations
  • Graph linear functions using two points method
  • Find equations of straight lines from given points
  • Solve linear inequalities graphically and algebraically
  • Determine positive and negative regions of linear functions
  • Apply linear functions to real-world phenomena and situations

Understanding Linear Functions

Complete explanation with examples

A linear function, as it is called, is an algebraic expression that represents the graph of a straight line.

When we talk about functions, it's important to highlight that the graphs of functions are represented in an axis system where there is a horizontal axis X X and a vertical axis Y Y .

A - Linear Function

Linear functions can be expressed by the expressions y=mx y = mx or y=mx+b y = mx + b , where m represents the slope of the line while b b (when it exists) represents the y-intercept.

To plot a linear function, all we need are 2 2 points. If the linear function is given, you can substitute a value for X X and obtain the corresponding Y Y value.

Detailed explanation

Practice Linear Functions

Test your knowledge with 20 quizzes

Given the linear function:

\( y=1-4x \)

What is the rate of change of the function?

Examples with solutions for Linear Functions

Step-by-step solutions included
Exercise #1

For the function in front of you, the slope is?

XY

Step-by-Step Solution

For this problem, we need to determine the nature of the slope for a given straight line on a graph.

Based on the graph provided, the red line starts at a higher point on the left (Y-axis) and moves downward toward a lower point on the right (X-axis). This indicates that as one moves from left to right across the graph, the function decreases in value. Consequently, this is typical of a line that has a negative slope.

The slope of a line is typically defined as the "rise over the run," or the ratio of the change in the vertical direction to the change in the horizontal direction. Here, as we proceed from left to right, the line goes "downwards" (negative rise), establishing a negative slope.

Thus, we can conclude that the slope of the line is negative.

Therefore, the solution to the problem is Negative slope.

Answer:

Negative slope

Video Solution
Exercise #2

For the function in front of you, the slope is?

XY

Step-by-Step Solution

To determine the slope of the line segment shown in the graph, follow these steps:

  • Identify the line segment on the graph; it's shown as a red line from one point to another.
  • Examine the direction the line segment travels from the leftmost point to the rightmost point.
  • Visually analyze whether the line segment is rising or falling as it moves from left to right.

Here is the detailed analysis:
- The red line segment starts lower on the left side and ends higher on the right side.
- This suggests that as we move from left to right, the line is rising.
- In terms of slope, a line that rises as it moves from left to right has a positive slope.

Therefore, the slope of the line segment is positive.

Thus, the correct answer is Positive slope.

Answer:

Positive slope

Video Solution
Exercise #3

For the function in front of you, the slope is?

XY

Step-by-Step Solution

To determine the slope of the line shown on the graph, we perform a visual analysis:

  • We examine the orientation of the line from left to right.
  • The red line starts at a higher point on the left and descends to a lower point on the right.
  • This indicates a downward movement, which corresponds to a negative slope.

Therefore, by observing the direction of the line, we conclude that the slope of the function is negative. This positional evaluation confirms that the correct answer is negative slope.

Answer:

Negative slope

Video Solution
Exercise #4

For the function in front of you, the slope is?

XY

Step-by-Step Solution

To determine the slope of the line, we'll examine the direction of the line segment on the graph:

  • The line depicted moves from the top left, passing through a point with higher y y -coordinate values, to the bottom right, ending at a point with lower y y -coordinate values.
  • This movement indicates that as x x increases (the direction to the right along the x x -axis), the y y -coordinate decreases.
  • When the y y -value reduces as the x x -value grows, the slope m m is negative.

Since the line descends from left to right, the slope of the line is negative.

Therefore, the slope of the function is a negative slope.

Answer:

Negative slope

Video Solution
Exercise #5

For the function in front of you, the slope is?

XY

Step-by-Step Solution

To solve this problem, follow these steps:

  • Step 1: Observe the given graph and the plotted line.
  • Step 2: Determine the direction of the line as it moves from left to right across the graph.
  • Step 3: Understand that a line moving downwards from left to right represents a negative slope.

Now, let's work through these steps:

Step 1: The graph shows a straight line that starts higher on the left side and descends towards the right side.

Step 2: As the line moves from left to right, it descends. This is a key indicator of the slope type.

Step 3: A line that moves downward from the left side to the right side of the graph (decreasing in height as it proceeds to the right) is characteristic of a negative slope. Conversely, a positive slope would show a line ascending as it moves rightward.

Therefore, the solution to the problem is the line has a negative slope.

Answer:

Negative slope

Video Solution

Frequently Asked Questions

How do you find the slope and y-intercept of a linear function?

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In the standard form y = mx + b, the slope is the coefficient m (the number multiplying x), and the y-intercept is the constant term b. For example, in y = 2x + 1, the slope is 2 and the y-intercept is 1.

What are the steps to graph a linear function?

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1. Identify two points by substituting x-values into the equation 2. Plot these points on the coordinate plane 3. Draw a straight line connecting the points 4. Extend the line in both directions with arrows

When is a linear function positive or negative?

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A linear function is positive when y > 0 (above the x-axis) and negative when y < 0 (below the x-axis). Find the x-intercept to determine where the function changes sign.

How do you know if a function is NOT linear?

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A function is NOT linear if: x is raised to a power (like x²), there's a square root of x, or the equation cannot be written in the form y = mx + b. Examples include y = x² and y = √x.

What does slope tell you about a linear function?

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Slope describes the steepness and direction of the line. If m > 0, the line slopes upward; if m < 0, it slopes downward; if m = 0, the line is horizontal (parallel to x-axis).

How do you find the equation of a line from two points?

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Use the slope formula m = (y₂ - y₁)/(x₂ - x₁) to find the slope, then substitute one point and the slope into y = mx + b to solve for b.

Can a linear function be parallel to the y-axis?

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No, a linear function can never be parallel to the y-axis. Such a line would be vertical (x = constant) and would not pass the vertical line test for functions.

What are different ways to write linear functions?

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Common forms include: y = mx + b (slope-intercept), y = mx (through origin), y = b (horizontal line), and rearranged forms like mx - y = b that can be solved for y.

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