Does anyone know or understand how to do this?

On an airplane there are two seats on the left side and three seats on the right side there are 90 seats o the right side of the plane

The expression 6x2 gives the surface area of a cube, and the expression x3 gives the volume of a cube, where x is the length of one side of the cube. find the surface area and the volume of a cube with a side length of 6m

Three numbers x, y, and z are in the ratio 2: 7: 8. if 12 is subtracted from y, then three numbers form a geometric sequence (in the order x, y–12, z). find x, y, and z. there are 2 sets.