Adding Rational Expressions

Oct 13, 2025 by wbrum.org 88 views

Introduction

Rational expressions are fractions that contain variables in the numerator or denominator. They are an essential part of algebra and are used to solve equations and inequalities. In this article, we will focus on adding rational expressions and simplifying the resulting expression.

What are Rational Expressions?

A rational expression is a fraction that contains variables in the numerator or denominator. It is written in the form of $\frac{p(x)}{q(x)}$ , where $p(x)$ and $q(x)$ are polynomials. Rational expressions can be added, subtracted, multiplied, and divided, just like regular fractions.

Adding Rational Expressions

To add rational expressions, we need to have a common denominator. The common denominator is the least common multiple (LCM) of the denominators of the two expressions. Once we have the common denominator, we can add the numerators and keep the denominator the same.

Example: Adding Rational Expressions

Let's consider the following example:

$\frac{5}{x+2}+\frac{6}{5-3}$

To add these two expressions, we need to find the common denominator, which is $(x+2)(5-3)$ . We can then rewrite each expression with the common denominator:

$\frac{5(5-3)}{(x+2)(5-3)}+\frac{6(x+2)}{(x+2)(5-3)}$

Now we can add the numerators:

$\frac{5(5-3)+6(x+2)}{(x+2)(5-3)}$

Simplifying the numerator, we get:

$\frac{5(2)+6(x+2)}{(x+2)(2)}$

Expanding the numerator, we get:

$\frac{10+6x+12}{2(x+2)}$

Combining like terms, we get:

$\frac{6x+22}{2(x+2)}$

Simplifying the Expression

To simplify the expression, we can divide both the numerator and the denominator by their greatest common divisor (GCD). In this case, the GCD of $6x+22$ and $2(x+2)$ is 2. Dividing both the numerator and the denominator by 2, we get:

$\frac{3x+11}{x+2}$

Conclusion

In this article, we learned how to add rational expressions and simplify the resulting expression. We saw that to add rational expressions, we need to have a common denominator, which is the least common multiple (LCM) of the denominators of the two expressions. We also learned how to simplify the expression by dividing both the numerator and the denominator by their greatest common divisor (GCD).

Answer

$The correct answer is C. $\frac{110-3}{x^2-6}$<br/> **Rational Expressions: Adding and Simplifying - Q&A**$

Introduction

In our previous article, we learned how to add rational expressions and simplify the resulting expression. In this article, we will answer some common questions related to rational expressions and provide additional examples to help you understand the concept better.

Q: What is the difference between a rational expression and a rational number?

A: A rational number is a number that can be expressed as the ratio of two integers, i.e., a fraction. A rational expression, on the other hand, is a fraction that contains variables in the numerator or denominator.

Q: How do I find the common denominator of two rational expressions?

A: To find the common denominator of two rational expressions, you need to find the least common multiple (LCM) of the denominators of the two expressions. You can do this by listing the multiples of each denominator and finding the smallest multiple that is common to both.

Q: Can I add rational expressions with different signs?

A: Yes, you can add rational expressions with different signs. When adding rational expressions with different signs, you need to find the common denominator and then add the numerators.

Q: How do I simplify a rational expression?

A: To simplify a rational expression, you need to divide both the numerator and the denominator by their greatest common divisor (GCD). This will help you to reduce the expression to its simplest form.

Q: Can I multiply rational expressions?

A: Yes, you can multiply rational expressions. When multiplying rational expressions, you need to multiply the numerators and denominators separately.

Q: How do I divide rational expressions?

A: To divide rational expressions, you need to invert the second expression and multiply. This means that you need to flip the numerator and denominator of the second expression and then multiply.

Q: Can I add rational expressions with different variables?

A: Yes, you can add rational expressions with different variables. When adding rational expressions with different variables, you need to find the common denominator and then add the numerators.

Example: Adding Rational Expressions with Different Variables

Let's consider the following example:

$\frac{2x}{x+1}+\frac{3y}{y+2}$

To add these two expressions, we need to find the common denominator, which is $(x+1)(y+2)$ . We can then rewrite each expression with the common denominator:

$\frac{2x(y+2)}{(x+1)(y+2)}+\frac{3y(x+1)}{(x+1)(y+2)}$

Now we can add the numerators:

$\frac{2xy+4x+3yx+3y}{(x+1)(y+2)}$

Simplifying the numerator, we get:

$\frac{5xy+4x+3y}{(x+1)(y+2)}$

Conclusion

In this article, we answered some common questions related to rational expressions and provided additional examples to help you understand the concept better. We learned how to find the common denominator of two rational expressions, how to add rational expressions with different signs, and how to simplify a rational expression.

Frequently Asked Questions

Q: What is the difference between a rational expression and a rational number?
A: A rational number is a number that can be expressed as the ratio of two integers, i.e., a fraction. A rational expression, on the other hand, is a fraction that contains variables in the numerator or denominator.
Q: How do I find the common denominator of two rational expressions?
A: To find the common denominator of two rational expressions, you need to find the least common multiple (LCM) of the denominators of the two expressions.
Q: Can I add rational expressions with different signs?
A: Yes, you can add rational expressions with different signs.
Q: How do I simplify a rational expression?
A: To simplify a rational expression, you need to divide both the numerator and the denominator by their greatest common divisor (GCD).
Q: Can I multiply rational expressions?
A: Yes, you can multiply rational expressions.
Q: How do I divide rational expressions?
A: To divide rational expressions, you need to invert the second expression and multiply.
Q: Can I add rational expressions with different variables?
A: Yes, you can add rational expressions with different variables.

Answer

The correct answer is C. $\frac{110-3}{x^2-6}$