Write these as inequalities

The Sydney Opera House can house no more than 5738 people. Luisa Miller always brings crowds of at least 4,000 people. What is the maximum number of empty seats that might not be filled during her performance?

Keiko is trying to score in the “ryō” range in her math class which is above a 70. Her test scores so far are 85, 57, and 78. What is the lowest score that she can get on her next test in order to stay in the ryō range when her scores are averaged?

Money in Brazil is called a Real (abbreviated R$). Davi starts a coffee business. He makes 3.82 R$ for every cup of coffee sold. How many cups would he need to sell to make at least 500 R$ profit?

5738-4000 = 1738

since the total seats <= 5738, the max unsold is <= 1738
since the minimum sold seats is >= 4000, the max unsold could be even less, so it's still <= 1738

your turn

I've already done that math, I need help on the next steps