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

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 #2

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

XY

Step-by-Step Solution

To solve this problem, we need to determine the slope of the line depicted on the graph.

First, understand that the slope of a line on a coordinate plane indicates how steep the line is and the direction it is heading. Specifically:

  • A positive slope means the line rises as it goes from left to right.
  • A negative slope means the line falls as it goes from left to right.

Let's examine the graph given:

  • We see that the line starts at a higher point on the left and descends to a lower point on the right side.
  • As we move from the left side of the graph towards the right, the line goes downwards.

This downward trajectory clearly indicates a negative slope because the line is declining as we move horizontally left to right.

Therefore, the slope of this function is Negative.

The correct answer is, therefore, Negative slope.

Answer:

Negative slope

Video Solution
Exercise #3

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

XY

Step-by-Step Solution

To solve this problem, let's analyze the given graph of the function to determine the slope's sign.

The slope of a line on a graph indicates the line's direction. A line with a positive slope rises as it moves from left to right, indicating that for every step taken to the right (along the x-axis), we move upward. Conversely, a line with a negative slope falls as it moves from left to right, meaning each step to the right results in moving downward.

Examining the graph provided, the red line starts higher on the left and goes downward towards the right visually. This indicates that the line is rising as it goes from left to right, which confirms it has a positive slope.

Therefore, the solution to the problem, regarding the slope of the line, is that it is a Positive slope.

Answer:

Positive slope

Video Solution
Exercise #4

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

XY

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Visual Inspection – Examine the red line on the graph to determine direction.
  • Step 2: Determine Slope Direction – Ascertain if the line rises or falls as it moves from left to right.
  • Step 3: Compare with Possible Answers – Verify which choice aligns with the determined slope direction.

Now, let's work through each step:
Step 1: The graph shows a red line segment, oriented in a manner that moves from left (lower) to right (higher).
Step 2: As the red line moves from the left toward the right side of the graph, it rises, indicating an upward trend and suggesting a positive slope.
Step 3: Given that the line increases from left to right, the slope is positive.

Therefore, the solution to the problem is Positive slope.

Answer:

Positive slope

Video Solution
Exercise #5

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

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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