Suppose a varies directly as b, and a=21 when b=6. find a when b=28

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?

If a revenue in total for a month was $9,950, fixed expenses were $9,000, and variable expenses were $300 what would be the total profit/ loss for the month?

Jenny made a scale drawing of a city. the scale she used was 5 inches = 1 yard. what is the scale factor of the drawing?