Multiplying Exponential Expressions

Oct 13, 2025 by wbrum.org 138 views

Understanding Scientific Notation

Scientific notation is a way of expressing very large or very small numbers in a more manageable form. It consists of a number between 1 and 10 multiplied by a power of 10. For example, the number 400 can be expressed in scientific notation as $4 \times 10^2$ . This format makes it easier to perform calculations and comparisons.

Multiplying Exponential Expressions

When multiplying exponential expressions in scientific notation, we multiply the coefficients (numbers in front of the powers of 10) and add the exponents. This is based on the rule that $a^m \times a^n = a^{m+n}$ .

The Problem

We are given the expression $\left(8.5 \times 10^3\right)\left(2 \times 10^5\right)$ and asked to express the result in scientific notation.

Step 1: Multiply the Coefficients

The coefficients are 8.5 and 2. Multiplying them together gives us $8.5 \times 2 = 17$ .

Step 2: Add the Exponents

The exponents are 3 and 5. Adding them together gives us $3 + 5 = 8$ .

Step 3: Write the Result in Scientific Notation

Now that we have the product of the coefficients (17) and the sum of the exponents (8), we can write the result in scientific notation. The result is $1.7 \times 10^8$ .

Comparing the Result to the Options

Looking at the options provided, we see that $1.7 \times 10^8$ is not among them. However, we can rewrite $1.7 \times 10^8$ as $1.7 \times 10^7 \times 10$ . Since $10 = 10^1$ , we can rewrite the expression as $1.7 \times 10^7 \times 10^1 = 1.7 \times 10^{7+1} = 1.7 \times 10^8$ . However, we can also rewrite $1.7 \times 10^8$ as $1.7 \times 10^7 \times 10^1 = 1.7 \times 10^7 \times 10 = 1.7 \times 10^8$ . This is the same as the original expression, but with the exponent increased by 1. Therefore, we can conclude that the correct answer is $1.7 \times 10^8$ .

However, since $1.7 \times 10^8$ is not among the options, we can try to rewrite it as $1.7 \times 10^7 \times 10 = 1.7 \times 10^8$ . This is the same as the original expression, but with the exponent increased by 1. Therefore, we can conclude that the correct answer is $1.7 \times 10^8$ .

Q: What is scientific notation?

A: Scientific notation is a way of expressing very large or very small numbers in a more manageable form. It consists of a number between 1 and 10 multiplied by a power of 10.

Q: How do I multiply exponential expressions in scientific notation?

A: When multiplying exponential expressions in scientific notation, you multiply the coefficients (numbers in front of the powers of 10) and add the exponents. This is based on the rule that $a^m \times a^n = a^{m+n}$ .

Q: Can you give an example of multiplying exponential expressions in scientific notation?

A: Let's say we want to multiply $\left(8.5 \times 10^3\right)\left(2 \times 10^5\right)$ . To do this, we multiply the coefficients (8.5 and 2) to get 17, and add the exponents (3 and 5) to get 8. The result is $1.7 \times 10^8$ .

Q: How do I add exponential expressions in scientific notation?

A: When adding exponential expressions in scientific notation, you add the exponents and keep the same coefficient. This is based on the rule that $a^m + a^n = a^m \times a^n \div a^n = a^m$ .

Q: Can you give an example of adding exponential expressions in scientific notation?

A: Let's say we want to add $\left(3 \times 10^2\right) + \left(2 \times 10^2\right)$ . To do this, we add the exponents (2 and 2) to get 4, and keep the same coefficient (3). The result is $3 \times 10^4$ .

Q: How do I subtract exponential expressions in scientific notation?

A: When subtracting exponential expressions in scientific notation, you subtract the exponents and keep the same coefficient. This is based on the rule that $a^m - a^n = a^m \div a^n \times a^n = a^{m-n}$ .

Q: Can you give an example of subtracting exponential expressions in scientific notation?

A: Let's say we want to subtract $\left(5 \times 10^3\right) - \left(2 \times 10^3\right)$ . To do this, we subtract the exponents (3 and 3) to get 1, and keep the same coefficient (5). The result is $5 \times 10^1$ .

Q: How do I divide exponential expressions in scientific notation?

A: When dividing exponential expressions in scientific notation, you divide the coefficients and subtract the exponents. This is based on the rule that $a^m \div a^n = a^{m-n}$ .

Q: Can you give an example of dividing exponential expressions in scientific notation?

A: Let's say we want to divide $\left(6 \times 10^4\right) \div \left(3 \times 10^2\right)$ . To do this, we divide the coefficients (6 and 3) to get 2, and subtract the exponents (4 and 2) to get 2. The result is $2 \times 10^2$ .

Q: What are some common mistakes to avoid when working with exponential expressions in scientific notation?

A: Some common mistakes to avoid when working with exponential expressions in scientific notation include:

Forgetting to multiply or divide the coefficients
Forgetting to add or subtract the exponents
Not keeping the same coefficient when adding or subtracting exponential expressions
Not using the correct rules for multiplying, dividing, adding, and subtracting exponential expressions

Q: How can I practice working with exponential expressions in scientific notation?

A: You can practice working with exponential expressions in scientific notation by:

Using online resources and practice problems
Working with real-world examples and applications
Creating your own practice problems and exercises
Asking a teacher or tutor for help and guidance

Q: What are some real-world applications of exponential expressions in scientific notation?

A: Exponential expressions in scientific notation have many real-world applications, including:

Calculating population growth and decay
Modeling chemical reactions and processes
Analyzing data and trends in science and engineering
Solving problems in physics, chemistry, and biology

By understanding and working with exponential expressions in scientific notation, you can develop a deeper understanding of mathematical concepts and apply them to real-world problems and applications.