Multiplying exponents instead of adding

Oct 13, 2025 by miodeya.com 113 views

Understanding Exponent Rules

Exponents are a fundamental concept in mathematics, and understanding the rules governing them is crucial for simplifying expressions. In this article, we will explore the common mistake made by Blake in simplifying the expression $\left(\frac{x^{12}}{x^{-3}}\right)^5$ .

The Correct Approach

To simplify the given expression, we need to apply the quotient of powers rule, which states that when dividing two powers with the same base, we subtract the exponents. In this case, we have:

\left(\frac{x^{12}}{x^{-3}}\right)^5 = \left(x^{12-(-3)}\right)^5 = \left(x^{15}\right)^5

Now, we can apply the power of a power rule, which states that when raising a power to another power, we multiply the exponents. Therefore:

\left(x^{15}\right)^5 = x^{15 \times 5} = x^{75}

Blake's Mistake

Blake's mistake was in applying the power of a power rule incorrectly. He multiplied the exponent in the numerator instead of multiplying the exponents. This resulted in the incorrect answer $\frac{1}{x^{20}}$ .

Why Did Blake Make This Mistake?

Blake's mistake can be attributed to a lack of understanding of the exponent rules. He may have confused the power of a power rule with the rule for multiplying exponents. When multiplying exponents with the same base, we add the exponents, not multiply them. For example:

x^a \times x^b = x^{a+b}

In contrast, when raising a power to another power, we multiply the exponents:

(x^a)^b = x^{a \times b}

Conclusion

In conclusion, Blake's mistake was in applying the power of a power rule incorrectly. He multiplied the exponent in the numerator instead of multiplying the exponents. This resulted in the incorrect answer $\frac{1}{x^{20}}$ . To avoid making this mistake, it is essential to understand the exponent rules and apply them correctly.

Common Mistakes to Avoid

When simplifying expressions with exponents, it is essential to avoid the following common mistakes:

Multiplying exponents instead of adding: When multiplying exponents with the same base, we add the exponents, not multiply them.
Not applying the power of a power rule: When raising a power to another power, we multiply the exponents, not add them.
Not simplifying the expression correctly: Make sure to apply the exponent rules correctly and simplify the expression to its simplest form.

Practice Problems

To practice simplifying expressions with exponents, try the following problems:

Simplify the expression $\left(\frac{x^8}{x^2}\right)^3$ .
Simplify the expression $\left(x^4\right)^5$ .
Simplify the expression $\left(\frac{x^6}{x^3}\right)^2$ .

Answer Key

$\left(\frac{x^8}{x^2}\right)^3 = \left(x^{8-2}\right)^3 = \left(x^6\right)^3 = x^{6 \times 3} = x^{18}$
$\left(x^4\right)^5 = x^{4 \times 5} = x^{20}$
$\left(\frac{x^6}{x^3}\right)^2 = \left(x^{6-3}\right)^2 = \left(x^3\right)^2 = x^{3 \times 2} = x^6$

Q: What is the quotient of powers rule?

A: The quotient of powers rule states that when dividing two powers with the same base, we subtract the exponents. For example:

\frac{x^a}{x^b} = x^{a-b}

Q: What is the power of a power rule?

A: The power of a power rule states that when raising a power to another power, we multiply the exponents. For example:

(x^a)^b = x^{a \times b}

Q: How do I simplify an expression with exponents?

A: To simplify an expression with exponents, follow these steps:

Apply the quotient of powers rule to simplify the expression inside the parentheses.
Apply the power of a power rule to simplify the expression.
Simplify the expression to its simplest form.

Q: What is the difference between multiplying exponents and raising a power to another power?

A: When multiplying exponents with the same base, we add the exponents:

x^a \times x^b = x^{a+b}

When raising a power to another power, we multiply the exponents:

(x^a)^b = x^{a \times b}

Q: How do I avoid making common mistakes when simplifying expressions with exponents?

A: To avoid making common mistakes when simplifying expressions with exponents, follow these tips:

Read the problem carefully: Make sure to understand the problem and the rules governing exponents.
Apply the exponent rules correctly: Make sure to apply the quotient of powers rule and the power of a power rule correctly.
Simplify the expression to its simplest form: Make sure to simplify the expression to its simplest form.

Q: What are some common mistakes to avoid when simplifying expressions with exponents?

A: Some common mistakes to avoid when simplifying expressions with exponents include:

Multiplying exponents instead of adding: When multiplying exponents with the same base, we add the exponents, not multiply them.
Not applying the power of a power rule: When raising a power to another power, we multiply the exponents, not add them.
Not simplifying the expression correctly: Make sure to apply the exponent rules correctly and simplify the expression to its simplest form.

Q: How do I practice simplifying expressions with exponents?

A: To practice simplifying expressions with exponents, try the following:

Practice problems: Try simplifying expressions with exponents using practice problems.
Real-world applications: Apply the exponent rules to real-world problems, such as finance, science, and engineering.
Online resources: Use online resources, such as video tutorials and practice problems, to help you practice simplifying expressions with exponents.

Q: What are some advanced topics in simplifying expressions with exponents?

A: Some advanced topics in simplifying expressions with exponents include:

Negative exponents: Learn how to simplify expressions with negative exponents.
Fractional exponents: Learn how to simplify expressions with fractional exponents.
Exponent rules with multiple bases: Learn how to simplify expressions with multiple bases and exponents.

By following these tips and practicing simplifying expressions with exponents, you can become proficient in simplifying expressions with exponents and apply the exponent rules to real-world problems.