Skip to main content
뒤로

Step-by-Step Guidance for Solving Linear Inequalities and Expressing Solutions in Interval Notation

스터디 가이드 - 스마트 노트

자료에 맞춘 맞춤형 노트, 핵심 정의, 예시, 맥락을 확장해 제공합니다.

Q1. Solve the following inequality. Write the solution set using interval notation:

19 + 7x \geq 2x - 5

Background

Topic: Linear Inequalities

This question tests your ability to solve a linear inequality and express the solution set using interval notation.

Key Terms and Formulas:

  • Linear Inequality: An inequality involving a linear expression, such as $ax + b \leq c$.

  • Interval Notation: A way to describe the set of solutions using parentheses and/or brackets.

Step-by-Step Guidance

  1. Start by isolating the variable $x$ on one side. Subtract $2x$ from both sides:

    $19 + 7x - 2x \geq -5$

  2. Simplify the left side by combining like terms:

    $19 + 5x \geq -5$

  3. Subtract $19$ from both sides to further isolate $x$:

    $5x \geq -5 - 19$

  4. Simplify the right side and prepare to solve for $x$ by dividing both sides by $5$.

Try solving on your own before revealing the answer!

Final Answer:

$x \geq -\frac{24}{5}$

In interval notation, the solution set is $\left[ -\frac{24}{5}, \infty \right)$.

We isolated $x$ and expressed the solution using the correct interval notation for a "greater than or equal to" inequality.

Q2. Solve the following inequality. Write the solution set in interval notation:

7(x - 3) \leq 2(4x - 1)

Background

Topic: Linear Inequalities with Distribution

This question tests your ability to solve inequalities that require distributing and combining like terms before isolating the variable.

Key Terms and Formulas:

  • Distributive Property: $a(b + c) = ab + ac$

  • Interval Notation: Used to express the solution set.

Step-by-Step Guidance

  1. Apply the distributive property to both sides:

    $7x - 21 \leq 8x - 2$

  2. Get all terms involving $x$ on one side and constants on the other. Subtract $7x$ from both sides:

    $-21 \leq x - 2$

  3. Add $2$ to both sides to isolate $x$:

    $-21 + 2 \leq x$

  4. Simplify the left side and write the solution in $x \geq$ form, then express in interval notation.

Try solving on your own before revealing the answer!

Final Answer:

$x \geq -19$

In interval notation, the solution set is $[-19, \infty)$.

We used the distributive property and isolated $x$ to find the solution set.

Q3. Solve the following inequality. Write the solution set in interval notation:

-3(x - 1) < -2[5 + 8(x + 5)]

Background

Topic: Linear Inequalities with Distribution and Combining Like Terms

This question tests your ability to handle distribution, combining like terms, and solving inequalities with negative coefficients.

Key Terms and Formulas:

  • Distributive Property: $a(b + c) = ab + ac$

  • Combining Like Terms: Add or subtract terms with the same variable.

Step-by-Step Guidance

  1. Distribute $-3$ on the left and $-2$ on the right:

    $-3x + 3 < -2 \times 5 - 2 \times 8(x + 5)$

  2. Simplify the right side by distributing $-2$ to both $5$ and $8(x + 5)$, then expand $8(x + 5)$.

  3. Combine like terms on both sides to get all $x$ terms on one side and constants on the other.

  4. Isolate $x$ and prepare to divide by the coefficient of $x$ (remember to reverse the inequality if dividing by a negative).

Try solving on your own before revealing the answer!

Final Answer:

$x > -\frac{8}{13}$

In interval notation, the solution set is $\left( -\frac{8}{13}, \infty \right)$.

We distributed, combined like terms, and solved for $x$, remembering to reverse the inequality when dividing by a negative.

Q4. Solve.

\frac{1}{2} + \frac{3}{7} \geq \frac{x}{14}

Background

Topic: Linear Inequalities with Fractions

This question tests your ability to solve inequalities involving fractions and to express the solution in terms of $x$.

Key Terms and Formulas:

  • Common Denominator: To add or compare fractions, rewrite them with a common denominator.

  • Solving for $x$: Isolate $x$ on one side of the inequality.

Step-by-Step Guidance

  1. Find a common denominator for the fractions on the left side.

  2. Add the fractions together to get a single fraction on the left.

  3. Set up the inequality so that you have a single fraction on each side: $\frac{a}{b} \geq \frac{x}{14}$.

  4. Multiply both sides by $14$ to clear the denominators and solve for $x$.

Try solving on your own before revealing the answer!

Final Answer:

$x \leq 13$

The solution set is $(-\infty, 13]$ in interval notation.

We combined the fractions, isolated $x$, and expressed the solution using interval notation.

Q5. Solve the following inequality. Write the solution set using interval notation:

3(x - 6) + 3x - 10 \geq 2(x - 8) + 10x

Background

Topic: Linear Inequalities with Distribution and Combining Like Terms

This question tests your ability to distribute, combine like terms, and solve for $x$ in a linear inequality.

Key Terms and Formulas:

  • Distributive Property: $a(b + c) = ab + ac$

  • Combining Like Terms: Add or subtract terms with the same variable.

Step-by-Step Guidance

  1. Distribute $3$ on the left and $2$ on the right:

    $3x - 18 + 3x - 10 \geq 2x - 16 + 10x$

  2. Combine like terms on both sides to simplify the inequality.

  3. Get all $x$ terms on one side and constants on the other.

  4. Isolate $x$ and prepare to divide by the coefficient of $x$ to solve.

Try solving on your own before revealing the answer!

Final Answer:

$x \geq 0$

The solution set is $[0, \infty)$ in interval notation.

We distributed, combined like terms, and isolated $x$ to find the solution set.

Q6. Solve the inequality:

4x + 1 < 4(x - 2)

Background

Topic: Linear Inequalities with Distribution

This question tests your ability to solve a linear inequality that requires distributing and isolating the variable.

Key Terms and Formulas:

  • Distributive Property: $a(b + c) = ab + ac$

  • Solving for $x$: Isolate $x$ on one side of the inequality.

Step-by-Step Guidance

  1. Distribute $4$ on the right side:

    $4x + 1 < 4x - 8$

  2. Subtract $4x$ from both sides to get all $x$ terms on one side:

    $1 < -8$

  3. Analyze the resulting statement to determine if there are any solutions or if the solution set is empty.

Try solving on your own before revealing the answer!

Final Answer:

There is no solution because $1 < -8$ is never true.

The solution set is $\emptyset$ (the empty set).

Reference Table for Interval Notation and Graphs

Table showing set notation, graph, and interval notation for inequalities

This table summarizes how to write solution sets for inequalities using set notation, graph, and interval notation. Use it as a reference when expressing your answers.

Pearson Logo

스터디 프렙