What is the difference of the volumes of the two oblique pyramids, both of which have square bases? Round the volumes to the nearest tenth of a centimeter.

Jackie purchased 3 bottles of water and 2 cups of coffee for a family for $7.35. brian 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? i need this done

How many different three-digit numbers can be formed using the digits 1 comma 2 comma 9 comma 6 comma 4 comma 3 comma and 8 without repetition? for example, 664 is not allowed.

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?