Conquering Inequalities: A Step-by-Step Guide

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Conquering Inequalities: A Step-by-Step Guide

Hey guys! Let's dive into the world of inequalities and learn how to solve them like pros. We'll break down the process step-by-step, making it super easy to understand. So, grab your pencils and let's get started. We'll be tackling three specific inequality problems, providing detailed explanations and strategies to help you master this fundamental algebra concept. The goal here is to not just solve the problems, but to truly understand the 'why' behind each step. Ready to become inequality ninjas? Let's go!

1. Solving the Inequality: 1/(x+1) > 5

Alright, let's start with the first problem: 1/(x+1) > 5. This one might look a bit intimidating at first, but don't worry, we'll break it down into manageable chunks. The key to solving inequalities like this is to isolate the variable, 'x', on one side of the inequality sign. But before we begin, it's crucial to acknowledge the domain restrictions. Specifically, x cannot equal -1 because that would make the denominator zero, resulting in an undefined expression. Remember this, as it's a critical detail when we write our final solution.

Now, let's proceed with solving the inequality. The most straightforward approach is to eliminate the fraction. To do this, we can multiply both sides of the inequality by (x+1). But here's the kicker: when you multiply or divide an inequality by a negative number, you need to flip the inequality sign. Since we don't know the sign of (x+1), we need to consider two cases:

Case 1: (x + 1) > 0 (i.e., x > -1)

In this case, we're multiplying by a positive number, so the inequality sign remains the same. The equation is modified as follows:

1 > 5(x + 1) 1 > 5x + 5 -4 > 5x x < -4/5

But remember our condition: x > -1. There's no value of x that satisfies both x < -4/5 and x > -1. Thus, there is no solution within this range.

Case 2: (x + 1) < 0 (i.e., x < -1)

Here, we are multiplying by a negative number, so we flip the inequality sign:

1 < 5(x + 1) 1 < 5x + 5 -4 < 5x x > -4/5

Again, we have a contradiction, x < -1 and x > -4/5. This also gives no solution.

So, there is no solution to the inequality.


2. Solving the Inequality: |x - 2| ≤ 3

Next up, we have an inequality involving absolute values: |x - 2| ≤ 3. This one deals with the distance of a number from zero. Remember, the absolute value of a number is its distance from zero, always resulting in a non-negative value. To solve this, we can rewrite the absolute value inequality as a compound inequality.

The definition of absolute value tells us that if |a| ≤ b, then -b ≤ a ≤ b. Therefore, we can rewrite |x - 2| ≤ 3 as:

-3 ≤ x - 2 ≤ 3

Now, let's solve for 'x'. We need to isolate 'x' in the middle. To do this, we add 2 to all three parts of the inequality:

-3 + 2 ≤ x - 2 + 2 ≤ 3 + 2 -1 ≤ x ≤ 5

Therefore, the solution to the inequality |x - 2| ≤ 3 is -1 ≤ x ≤ 5. This means that any value of 'x' between -1 and 5 (inclusive) will satisfy the inequality.

So, the final answer is x ∈ [-1, 5]. We've now solved the second inequality! Easy, right?


3. Solving the Inequality: |5x - 3| >/= -2

Now let's tackle the third and final inequality: |5x - 3| >/= -2. This one might seem tricky at first glance, but let's break it down. Remember that the absolute value of any real number is always non-negative (greater than or equal to zero). In other words, the absolute value of an expression is always 0 or positive.

Since the absolute value of any expression is always greater than or equal to zero, and zero is always greater than -2, the inequality |5x - 3| >/= -2 is true for all real numbers. No matter what value you substitute for x, the absolute value of (5x - 3) will always be greater than or equal to -2. This is because the absolute value can never be negative.

This means that there are no restrictions on the values of x that will make this inequality true. No matter the value of x, the absolute value will always be non-negative. This is an important concept in algebra, and this inequality highlights how this applies in a practical example.

So, the solution to the inequality |5x - 3| >/= -2 is all real numbers. This can be expressed in interval notation as (-∞, ∞).


Conclusion: Mastering Inequalities

That's a wrap, folks! We've successfully solved three different types of inequalities. We’ve covered everything from solving rational inequalities with domain considerations to absolute value inequalities that might seem complex at first glance. Remember the key takeaways: always consider the domain, remember to flip the sign when multiplying/dividing by a negative number, and understand the properties of absolute values. Practicing these steps will help you master the process.

Solving inequalities is a fundamental skill in algebra, and it forms the basis for more advanced mathematical concepts. If you understand the principles we went over today, you'll be well-prepared for more challenging problems in the future. Keep practicing, and don't be afraid to make mistakes – that's how we learn. Keep up the awesome work!


Additional Tips for Solving Inequalities

Here are some extra tips and tricks to help you become an inequality whiz:

  • Always check your solutions. Plug your answer back into the original inequality to make sure it's correct.
  • Visualize the solution on a number line. This can help you understand the solution set and avoid errors.
  • Practice, practice, practice! The more you practice, the more comfortable you'll become with solving inequalities.
  • Understand the different types of inequalities. Linear, quadratic, absolute value – each has its own nuances.
  • Break down complex inequalities. Don't try to solve everything at once. Simplify and isolate variables step-by-step.
  • Use interval notation. Get familiar with this notation to express your solutions clearly.

By following these steps and tips, you'll be well on your way to conquering any inequality that comes your way. Keep up the great work, and keep exploring the fascinating world of mathematics!