NEED HELP ASAP find the error and explain why it is wrong: laurel has to find the average rate of change of f(x) over the interval from x=6 to x=10 using the table below. what did she do wrong?

The point of intersection of the diagonals of a rectangle is 4 cm further away from the smaller side then from the larger side of the rectangle. the perimeter of the rectangle is equal to 56 cm. find the lengths of the sides of the rectangle. 16 points answer quick