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 28 quizzes

What is the solution to the inequality shown in the diagram?

-43

Examples with solutions for Linear Functions

Step-by-step solutions included
Exercise #1

What is the solution to the following inequality?

10x43x8 10x-4≤-3x-8

Step-by-Step Solution

In the exercise, we have an inequality equation.

We treat the inequality as an equation with the sign -=,

And we only refer to it if we need to multiply or divide by 0.

 10x43x8 10x-4 ≤ -3x-8

We start by organizing the sections:

10x+3x48 10x+3x-4 ≤ -8

13x48 13x-4 ≤ -8

13x4 13x ≤ -4

Divide by 13 to isolate the X

x413 x≤-\frac{4}{13}

Let's look again at the options we were asked about:

Answer A is with different data and therefore was rejected.

Answer C shows a case where X is greater than413 -\frac{4}{13} , although we know it is small, so it is rejected.

Answer D shows a case (according to the white circle) where X is not equal to413 -\frac{4}{13} , and only smaller than it. We know it must be large and equal, so this answer is rejected.

 

Therefore, answer B is the correct one!

Answer:

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, let's evaluate the graph of the line provided:

  • The line is visually represented as starting from the bottom left to the top right, moving upwards.
  • In a standard Cartesian graph, a line that ascends as it progresses from left to right implies a positive change in the y-coordinate as the x-coordinate increases.
  • This upward trajectory indicates that the slope, m m , is positive.

Thus, the slope of the function is positive.

Therefore, the answer 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, 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

Frequently Asked Questions

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

+
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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