Two identical number cubes are shown in the picture. The edge length of these number cubes is 3 centimeters what is the combined volume of the two number cubes in cubic centimeters

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm