Final answer:
The larger square Marta has, with a side length of 8 inches, has an area that is four times greater than the smaller square with a side length of 4 inches.
Step-by-step explanation:
The student asked about the length of a textbook cover given its width and area. To find the length, we would divide the area by the width. However, the provided information relates to a different mathematical problem involving squares and area. Marta has a square with a side length of 4 inches. When the dimensions are doubled, the side length of the larger square becomes 8 inches.
To find the area of the larger square, we square its side length, which yields 64 square inches. Comparatively, the smaller square with a side length of 4 inches has an area of 16 square inches. Therefore, the area of the larger square is four times greater than that of the smaller square because the square of the scale factor (2^2) is applied.
To find the length of the textbook cover, we can use the formula for the area of a rectangle which is length times width. In this case, the area is given as 80 square inches and the width is 8 inches. So, we can solve for the length by dividing the area by the width:
Length = Area / Width = 80 square inches / 8 inches = 10 inches
Therefore, the length of the textbook cover is 10 inches.