Math Problem Statement

Use a calculator to work out (3.4 × 10^8 × 8.2 × 10^9) ÷ (5.7 × 10^-3 − 9.6 × 10^-4). Give your answer in standard form to 2 significant figures.

Solution

Let's solve the problem from the uploaded image step by step.

We are tasked with evaluating:

3.4×108×8.2×1095.7×1039.6×104\frac{3.4 \times 10^8 \times 8.2 \times 10^9}{5.7 \times 10^{-3} - 9.6 \times 10^{-4}}

and presenting the answer in standard form to 2 significant figures.

Step 1: Calculate the numerator

The numerator is:

3.4×108×8.2×1093.4 \times 10^8 \times 8.2 \times 10^9

Multiply the constants 3.4×8.2=27.883.4 \times 8.2 = 27.88. For the powers of 10, add the exponents: 108×109=101710^8 \times 10^9 = 10^{17}

So, the numerator becomes: 27.88×101727.88 \times 10^{17}

Step 2: Calculate the denominator

The denominator is:

5.7×1039.6×1045.7 \times 10^{-3} - 9.6 \times 10^{-4}

Convert both terms to the same power of 10. Rewrite 5.7×1035.7 \times 10^{-3} as 57×10457 \times 10^{-4}. Subtract: 57×1049.6×104=(579.6)×104=47.4×10457 \times 10^{-4} - 9.6 \times 10^{-4} = (57 - 9.6) \times 10^{-4} = 47.4 \times 10^{-4}

Step 3: Combine numerator and denominator

Now divide: 27.88×101747.4×104\frac{27.88 \times 10^{17}}{47.4 \times 10^{-4}}

First, divide the constants: 27.8847.40.588\frac{27.88}{47.4} \approx 0.588

For the powers of 10, subtract the exponents: 1017÷104=102110^{17} \div 10^{-4} = 10^{21}

So, the result becomes: 0.588×10210.588 \times 10^{21}

Step 4: Convert to standard form

To write this in standard form, shift the decimal point of 0.5880.588 one place to the right, which increases the power of 10 by 1: 5.88×10205.88 \times 10^{20}

Step 5: Round to 2 significant figures

The rounded result is: 5.9×10205.9 \times 10^{20}

Final Answer:

5.9×10205.9 \times 10^{20}


Would you like a detailed breakdown of any step?
Here are 5 questions related to this problem for further practice:

  1. How do you handle subtraction involving powers of 10?
  2. What are the rules for multiplying numbers in scientific notation?
  3. How do you simplify expressions like 108×10910^8 \times 10^9?
  4. What is the importance of writing results in standard form?
  5. How do you round a number to a specific number of significant figures?

Tip: Always align the exponents before performing addition or subtraction with numbers in scientific notation.

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Math Problem Analysis

Mathematical Concepts

Scientific Notation
Arithmetic Operations
Standard Form
Significant Figures

Formulas

Multiplication of powers: a^m × a^n = a^(m+n)
Division of powers: a^m ÷ a^n = a^(m−n)
Scientific notation subtraction: Align powers before subtraction

Theorems

Laws of Exponents

Suitable Grade Level

Grades 9-11