To solve this problem, let's first understand the conversion between US dollars (USD) and Australian dollars (AUD) provided in the image:

1. Conversion rates given:
   • 1 USD = 1.0643 AUD
   • 1 AUD = 0.9408 USD

The question asks for the expression that converts 80 US dollars (USD) to Australian dollars (AUD).

Conversion Steps:

1. Start with 80 USD.
2. Use the conversion rate from USD to AUD:

$\text{Amount in AUD} = \text{Amount in USD} \times \text{Conversion rate (USD to AUD)}$

Given that 1 USD = 1.0643 AUD, the expression to convert 80 USD to AUD would be:

$80 \times 1.0643$

Now, let's match this expression with the options provided in the image:

• Option B shows $80 \times \frac{1.0643}{1}$, which simplifies to $80 \times 1.0643$.

Therefore, Option B is the correct choice to convert 80 USD to AUD.

Answer:

The correct expression is Option B: $80 \times \frac{1.0643}{1}$.

Would you like more details or have any questions?

Here are 5 related questions to expand your understanding:

1. How do you convert Australian dollars to US dollars given the reverse exchange rate?
2. If the exchange rate changes, how would that affect the conversion calculation?
3. How would you convert 100 AUD to USD using the given exchange rates?
4. What mathematical steps are involved in finding the exchange rate from AUD to USD if only the USD to AUD rate is provided?
5. Can you calculate the equivalent value in AUD for 150 USD using the given conversion rate?

Tip: Always ensure to use the most recent exchange rates for currency conversions as they fluctuate frequently.