What is 8^-2·a^7 this is for my math homework

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?

Typically a point in a three dimensional cartesian coordinate system is represented by which of the following answers in the picture !

Simplify the given expression leaving the answer in improper fraction form. 2/3+5/6