The landscaper pours 200 gallons of herbicide in a pond. the herbicide degrades 10% each week. the landscaper will put another dose in the pond when thr herbicide level drops below 50 gallons. in about how many weeks will he need to add more herbicide?

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?

Find the solutions for a triangle with a =16, c =12, and b = 63º

On traditional maps, earth is represented in a flat plane, or by euclidean geometry. however, a globe is a more accurate model that comes from elliptical geometry.how does a globe represent the fact that there are no parallel lines in elliptical geometry? the equator is not parallel to any other latitudinal lines. the north and south poles are never connected by a geodesic. the geodesics connecting the north and south poles never intersect. the geodesics connecting the north and south poles intersect at both of the poles.