Wei-min makes a square quilt that has an area of 100 square feet. it has 25 square blocks, each the same size. what is the length of each side of a block?

The area of each of the 25 square blocks is equal to 100 ft² divided by 25 which is equal to 4 ft². The area of square with side length equal to x is calculated through the equation,
                                     A = x² = 4 ft²
The value of x from the equation is 2 ft. Thus, the length of each square block is 2 ft.