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3.6 - Linear Equations in One Variable

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Introduction to Linear Equations

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Teacher
Teacher

Today, we're talking about linear equations in one variable! Who can tell me what a linear equation is?

Student 1
Student 1

I think it's an equation that makes a straight line when we graph it?

Teacher
Teacher

Exactly! A linear equation looks like this: ax + b = 0. Great job! Can anyone tell me what 'a' and 'b' represent?

Student 2
Student 2

Are they numbers?

Teacher
Teacher

Yes, they are real numbers! And remember, 'a' cannot be zero. That's important because we need 'a' to define our slope.

Student 3
Student 3

So if 'a' is zero, it won't be a linear equation?

Teacher
Teacher

Correct! Let's move on to how we can solve these equations. What do you think is the first step in solving ax + b = 0?

Student 4
Student 4

Maybe we need to get x alone on one side?

Teacher
Teacher

Right! We often do this by transposing terms. We will change the sign when moving terms across the equation. For example, if we have 3x + 2 = 0, we can move 2 to the other side. What does that look like?

Student 1
Student 1

It becomes 3x = -2!

Teacher
Teacher

Great! Now, to find 'x', we divide both sides by 3. Who can tell me what that gives us?

Student 2
Student 2

x = -2/3!

Teacher
Teacher

Excellent! Let's summarize: linear equations must be in the form ax + b = 0, and we solve them by transposing terms and isolating the variable. Any questions?

Combining Like Terms

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Teacher
Teacher

Now that we know how to isolate 'x', let's talk about combining like terms. What are like terms?

Student 3
Student 3

They have the same variable raised to the same power?

Teacher
Teacher

That's correct! It helps simplify our equations. For example, if I had 2x + 3x - 5 = 0, how would we combine the 'x' terms?

Student 4
Student 4

We add the coefficients! So that would be 5x - 5 = 0.

Teacher
Teacher

Exactly! Now if we isolate x from here, what do we do next?

Student 1
Student 1

Transpose the -5 across?

Teacher
Teacher

Yes! So we would get 5x = 5! What do we do next?

Student 2
Student 2

Divide both sides by 5, so x = 1!

Teacher
Teacher

Great work! So remember, combining like terms helps us simplify equations. Let's summarize: we combine coefficients of like terms to ease our solving process.

Isolating the Variable

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Teacher
Teacher

Finally, let's focus on isolating the variable. Why is that our ultimate goal in solving an equation?

Student 3
Student 3

So we can find out what 'x' is!

Teacher
Teacher

That’s right! If we don't isolate 'x', we won't know its value. Let's review: if we have 7x + 3 = 24, how would we isolate 'x'?

Student 4
Student 4

First, we would subtract 3, so 7x = 21.

Student 1
Student 1

And then divide by 7 to find x!

Teacher
Teacher

Perfect! So to sum up: isolating the variable is crucial because it helps us find its exact value. Understanding how to isolate 'x' will help solve any linear equation!

Introduction & Overview

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Quick Overview

This section introduces linear equations in one variable and the rules for solving these equations.

Standard

Linear equations in one variable are equations that can be expressed in the form ax + b = 0, where a and b are real numbers. The section emphasizes rules for solving these equations, such as transposing terms, combining like terms, and isolating the variable.

Detailed

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Audio Book

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Definition of Linear Equations

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An equation that can be written in the form:

a x + b = 0

Where:
● a ≠ 0
● x is the variable
● a, b are real numbers

Detailed Explanation

A linear equation in one variable takes a specific form, which is written as 'ax + b = 0'. Here, 'a' is a coefficient that must not be zero (a ≠ 0), and 'x' represents the variable we want to find. 'b' is another real number. This equation represents a straight line when graphed, hence the name 'linear'.

Examples & Analogies

Imagine you have a balance scale and you're trying to find out how much a single pencil weighs. You can represent this situation with a linear equation where 'x' is the weight of the pencil. The equation might look like '2x + 5 = 15', meaning that adding twice the weight of the pencil and 5 grams equals 15 grams. The goal is to figure out the weight of 'x'.

Rules for Solving Linear Equations

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Rules for Solving Linear Equations:
● Transpose terms across the equation by changing their sign.
● Combine like terms.
● Isolate the variable to find its value.

Detailed Explanation

To solve linear equations, we follow a series of steps: First, we transpose or move terms from one side of the equation to the other, which involves changing their sign. Next, we combine like terms to simplify the equation. Finally, we isolate the variable, which means we rearrange the equation so that 'x' (the variable) is alone on one side of the equation. This helps us to easily find the value of 'x'.

Examples & Analogies

Think of solving an equation like balancing items on both sides of a scale. If you move 3 apples from one side to the other, you have to change their status (from positive to negative) to keep the balance intact. For instance, if you start with 10 apples on the left and want to find out how many apples you have left after transferring some to the right, you rearrange the equation similarly until only the unknown remains.

Definitions & Key Concepts

Learn essential terms and foundational ideas that form the basis of the topic.

Key Concepts

  • Form of Linear Equations: Linear equations are generally of the form ax + b = 0, where a cannot be zero.

  • Transposing Terms: Moving terms across the equation while changing their signs is crucial for solving linear equations.

  • Combining Like Terms: Simplifying equations is made easier by combining coefficients of like terms.

  • Isolating Variables: The goal in solving linear equations is to isolate the variable, typically by rearranging the equation.

  • Real-World Application: Understanding linear equations is essential as they represent numerous real-life situations.

Examples & Real-Life Applications

See how the concepts apply in real-world scenarios to understand their practical implications.

Examples

  • Example 1: Solve the equation 3x + 4 = 10. After transposing, we find 3x = 6, leading to x = 2.

  • Example 2: In the equation 5x - 6 = 9, we can isolate x by adding 6, so 5x = 15, hence x = 3.

Memory Aids

Use mnemonics, acronyms, or visual cues to help remember key information more easily.

🎵 Rhymes Time

  • To solve an equation, don't stall or fidget, move terms around, and keep it legit!

📖 Fascinating Stories

  • Imagine you're at a treasure hunt. Your map has X marked on it, but to get to X, you first need to clear away the stones, which are like the terms you need to move in your equation.

🧠 Other Memory Gems

  • To solve equations, remember: T - C - I (Transpose, Combine, Isolate)!

🎯 Super Acronyms

The acronym 'EAT' can help

  • 'Evaluate'
  • 'Add/Subtract'
  • 'Transpose'.

Flash Cards

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Glossary of Terms

Review the Definitions for terms.

  • Term: Linear Equation

    Definition:

    An equation that can be written in the form ax + b = 0, where a ≠ 0 and x is the variable.

  • Term: Transpose

    Definition:

    To move a term from one side of an equation to the other, changing its sign.

  • Term: Combine Like Terms

    Definition:

    To add or subtract terms with the same variable and power to simplify an expression.

  • Term: Isolate

    Definition:

    To rearrange an equation to get a variable alone on one side.