How do I solve for pie?

7. if the value of x varies directly with the value of y, and x = 3 when y = 21. what is the valu y, and x = 3 when y = 21. what is the value of x when y = 105?

Rosy waxes 2/3 of her car with 1/4 bottle of car wax.at this rate,what fraction of the bottle of car wax will rosey use to wax her entire car

A3-dimensional figure has a square base and 4 lateral faces that meet at a point. explain the difference between the cross sections when a slice is made perpendicular to the base through the vertex, and when a slice is made perpendicular to the base and not through the vertex