[(5 x 2.34) - 9] divided by 2 Help needed

Which expression is equivalent to 16 in exponential form? a) 4 × 4 b) 8 × 2 c) 23 d) 24

Ineed with math stuff it involves graphs

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?