How do i solve this equation by linear combinations

What are correct trigonometric ratios that could be used to determine the length of ln

The holiday party will cost $160 if 8 people attend.if there are 40 people who attend the party, how much will the holiday party cost

Acoffee shop orders at most $3,500 worth of coffee and tea. the shop needs to make a profit of at least $1,900 on the order. the possible combinations of coffee and tea for this order are given by this system of inequalities, where c = pounds of coffee and t = pounds of tea: 6c + 13t ≤ 3,500 3.50c + 4t ≥ 1,900 which graph's shaded region represents the possible combinations of coffee and tea for this order?