3 4 ÷ 5 12 = 3 4 × help please

Which of the following parabolas opens down?

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?

What is the value of n in the equation -1/2(2n+4)+6=-9+4(2n+1)