Can someone please give me the equations for lines A, B, C, D, and E

Two variables, x and y, vary inversely, and x=12 when y=4. what is the value of y when x=3?

If the scale factor between two circles is 2x/5y what is the ratio of their areas?

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