To convert US dollars (USD) to Australian dollars (AUD), we need to use the exchange rate that gives us the corresponding amount in AUD for a given amount in USD.
Given the exchange rates:
[tex]\[
1 \text{ USD} = 1.0343 \text{ AUD}
\][/tex]
[tex]\[
1 \text{ AUD} = 0.9668 \text{ USD}
\][/tex]
We seek to convert 80 USD to AUD. The exchange rate we need is the one that directly converts USD to AUD:
[tex]\[
1 \text{ USD} = 1.0343 \text{ AUD}
\][/tex]
To find out how many AUD are equivalent to 80 USD, we multiply the amount in USD by the exchange rate:
[tex]\[
80 \text{ USD} \times \frac{1.0343 \text{ AUD}}{1 \text{ USD}}
\][/tex]
When we perform this multiplication:
[tex]\[
80 \text{ USD} \times 1.0343 \text{ AUD} / \text{ USD} = 82.744 \text{ AUD}
\][/tex]
So the correct expression to use is:
[tex]\[
80 \text{ USD} \times \frac{1.0343 \text{ AUD}}{1 \text{ USD}}
\][/tex]