Question

Error Analysis  Your friend says that the product of 2.1 times 10 Superscript 7 and 4 times 10 Superscript negative 5 is 8.4 times 10 Superscript negative 2. What is the correct​ product? What mistake did your friend likely​ make?
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Part 1
left parenthesis 2.1 times 10 Superscript 7 right parenthesis left parenthesis 4 times 10 Superscript negative 5 right parenthesisequals
  
enter your response here
​(Use scientific notation. Use the multiplication symbol in the math palette as​ needed.)

Answers

GPT-4o mini
To find the product of \( (2.1 \times 10^7) \) and \( (4 \times 10^{-5}) \), we can use the property of multiplication in scientific notation, which states:

\[
(a \times 10^m)(b \times 10^n) = (a \times b) \times 10^{(m + n)}
\]

### Step 1: Multiply the coefficients
First, we multiply the coefficients \( 2.1 \) and \( 4 \):

\[
2.1 \times 4 = 8.4
\]

### Step 2: Add the exponents
Next, we add the exponents of the powers of ten:

\[
7 + (-5) = 2
\]

### Step 3: Combine results
Now, we combine the results:

\[
(2.1 \times 10^7) \times (4 \times 10^{-5}) = 8.4 \times 10^2
\]

### Final Result
The correct product is:

\[
8.4 \times 10^2
\]

### Mistake Analysis
Your friend stated that the product was \( 8.4 \times 10^{-2} \). The mistake they likely made was in the addition of the exponents. They may have incorrectly calculated \( 7 + (-5) \) as \( -2 \) instead of \( 2 \).

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