Math Problem Statement

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Solve the set of inequalities and express each solution in interval notation.

Solution

I can help you solve the exercises in the image. I'll work through them one by one.

Let's start with the first two problems:

  1. 2x2x<62 \leq x^2 - x < 6

To solve this inequality:

  • Split into two parts: 2x2xandx2x<62 \leq x^2 - x \quad \text{and} \quad x^2 - x < 6

  • Solve the first part: 2x2xx2x202 \leq x^2 - x \quad \Rightarrow \quad x^2 - x - 2 \geq 0 Factor the quadratic: (x2)(x+1)0(x - 2)(x + 1) \geq 0 The critical points are x=2x = 2 and x=1x = -1. Using a sign chart, we find that the solution is x(,1][2,)x \in (-\infty, -1] \cup [2, \infty).

  • Solve the second part: x2x<6x2x6<0x^2 - x < 6 \quad \Rightarrow \quad x^2 - x - 6 < 0 Factor the quadratic: (x3)(x+2)<0(x - 3)(x + 2) < 0 The critical points are x=3x = 3 and x=2x = -2. Using a sign chart, the solution is x(2,3)x \in (-2, 3).

  • Now, combine the two results: (,1][2,)and(2,3)(-\infty, -1] \cup [2, \infty) \quad \text{and} \quad (-2, 3) The intersection gives the solution: x[1,1][2,3)x \in [-1, -1] \cup [2, 3)

  1. 3x22x<83 \leq x^2 - 2x < 8

To solve this inequality:

  • Split into two parts: 3x22xandx22x<83 \leq x^2 - 2x \quad \text{and} \quad x^2 - 2x < 8

  • Solve the first part: 3x22xx22x303 \leq x^2 - 2x \quad \Rightarrow \quad x^2 - 2x - 3 \geq 0 Factor the quadratic: (x3)(x+1)0(x - 3)(x + 1) \geq 0 The critical points are x=3x = 3 and x=1x = -1. Using a sign chart, we find that the solution is x(,1][3,)x \in (-\infty, -1] \cup [3, \infty).

  • Solve the second part: x22x<8x22x8<0x^2 - 2x < 8 \quad \Rightarrow \quad x^2 - 2x - 8 < 0 Factor the quadratic: (x4)(x+2)<0(x - 4)(x + 2) < 0 The critical points are x=4x = 4 and x=2x = -2. Using a sign chart, the solution is x(2,4)x \in (-2, 4).

  • Now, combine the two results: (,1][3,)and(2,4)(-\infty, -1] \cup [3, \infty) \quad \text{and} \quad (-2, 4) The intersection gives the solution: x[1,1][3,4)x \in [-1, -1] \cup [3, 4)


Would you like me to continue solving the next problems, or would you prefer further clarification on these? Here are some questions that might expand your understanding:

  1. How do you determine the sign of intervals in quadratic inequalities?
  2. What is a sign chart, and how is it useful in solving inequalities?
  3. How do we factor quadratic expressions like x22x3x^2 - 2x - 3?
  4. What is the process of combining the results of inequalities?
  5. How would the solution change if we had strict inequalities (i.e., << or >>)?

Tip:

When solving quadratic inequalities, always check the signs of the factors in each interval between critical points. This will help you determine where the inequality holds.

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Math Problem Analysis

Mathematical Concepts

Inequalities
Quadratic Equations
Factoring
Interval Notation
Sign Chart Analysis

Formulas

Quadratic Inequalities: ax^2 + bx + c < 0
Interval Notation: Using brackets and parentheses to denote ranges
Rational Inequalities: Involving fractions

Theorems

Quadratic Formula
Zero Product Property
Sign Chart Method

Suitable Grade Level

Grades 9-12