<image>Exploration and Application of Multiplication Formula:

(1) As shown in figure A, there is a small square with side length b inside a large square with side length a. Please write the area of the shaded part in the form of the difference of two squares: ______.
(2) Xiao Ying cuts out the shaded part and reassembles it into a rectangle, as shown in figure B. The length of the rectangle is ______, the width is ______, and the area is ______ (expressed in the form of polynomial multiplication).
(3) By comparing the shaded parts in figures A and B, the formula obtained is ______ (expressed as an equation).
(4) Using the formula you derived, calculate: 10.3×9.7.