On a map, 1 cm represents 30 km. Two cities on the map are 2.3 cm apart. How far apart at the actual cities?

Can someone explain the elimination method to me for this problem?

Jackie purchased 3 bottles of water and 2 cups of coffee for the family for $7.35. ryan bought 4 bottles of water and 1 cup of coffee for his family for 7.15. how much does each bottle of water cost? how much does each cup of coffee cost?

[15 points, algebra 2]simplify the complex fraction and find the restrictions.