Each edge of a cube is multiplied by 7 what happens to the volume of the cube?

The volume of the cube is Length x Width x Heigt, L x W x H. If you multiply the edges of the cube by seven you are multiplying the length width and height by seven. So the new volume will be 7 x L x 7 x W x 7 x H, which is the same as 7x7x7xLxWxH = 343 x LWH, i.e. if you multiply the edges of a cube by 7 you increase the volume by 7 cubed or 343. Hope this helps.