Understanding Exponents and Negative Powers

Oct 13, 2025 by wbrum.org 111 views

**Simplify the Expression: $(5)^{-3}$**

Understanding Exponents and Negative Powers

In mathematics, exponents are a shorthand way of representing repeated multiplication. For example, $5^3$ means $5 \times 5 \times 5$ . However, when we encounter a negative exponent, it can be a bit more challenging to understand. In this article, we will explore how to simplify the expression $(5)^{-3}$ .

What is a Negative Exponent?

A negative exponent is a way of expressing a fraction. When we have a negative exponent, it means that we are taking the reciprocal of the base number raised to the positive exponent. In other words, $a^{-n} = \frac{1}{a^n}$ .

Simplifying $(5)^{-3}$

Using the definition of a negative exponent, we can rewrite $(5)^{-3}$ as $\frac{1}{(5)^3}$ . Now, we need to simplify the expression inside the parentheses.

Calculating $(5)^3$

To calculate $(5)^3$ , we need to multiply $5$ by itself three times: $5 \times 5 \times 5 = 125$ . Therefore, $(5)^3 = 125$ .

Simplifying the Expression

Now that we have calculated $(5)^3$ , we can simplify the expression $\frac{1}{(5)^3}$ . This becomes $\frac{1}{125}$ .

Conclusion

In conclusion, the simplified expression for $(5)^{-3}$ is $\frac{1}{125}$ . This is the correct answer among the options provided.

Q&A

Q: What is the definition of a negative exponent? A: A negative exponent is a way of expressing a fraction. When we have a negative exponent, it means that we are taking the reciprocal of the base number raised to the positive exponent.

Q: How do we simplify a negative exponent? A: To simplify a negative exponent, we can rewrite it as the reciprocal of the base number raised to the positive exponent.

Q: What is the value of $(5)^3$ ? A: $(5)^3 = 5 \times 5 \times 5 = 125$ .

Q: What is the simplified expression for $(5)^{-3}$ ? A: The simplified expression for $(5)^{-3}$ is $\frac{1}{125}$ .

Q: Why is $\frac{1}{125}$ the correct answer? A: $\frac{1}{125}$ is the correct answer because it is the simplified expression for $(5)^{-3}$ .

Common Mistakes

Mistake 1: Not understanding the definition of a negative exponent.
Mistake 2: Not simplifying the expression correctly.
Mistake 3: Not calculating the value of $(5)^3$ correctly.

Tips and Tricks

Tip 1: Make sure to understand the definition of a negative exponent before attempting to simplify the expression.
Tip 2: Simplify the expression step by step to avoid mistakes.
Tip 3: Calculate the value of $(5)^3$ correctly to ensure that the expression is simplified correctly.

Practice Problems

Simplify the expression $(2)^{-4}$ .
Simplify the expression $(3)^{-2}$ .
Simplify the expression $(4)^{-1}$ .

Answer Key

$(2)^{-4} = \frac{1}{16}$
$(3)^{-2} = \frac{1}{9}$
$(4)^{-1} = \frac{1}{4}$