Calculate the square of 1949 - the square of 1950 + the square of 1951 - the square of 1952 + +The square of 1997 - the square of 1998 + the square of 1999

Calculate the square of 1949 - the square of 1950 + the square of 1951 - the square of 1952 + +The square of 1997 - the square of 1998 + the square of 1999

According to the square of a, the square of - (a + 1) = (2a + 1) the square of 1949-1950 + the square of 1951-1952 + +Square of 1997 - square of 1998 + square of 1999 = [square of 1949 - square of 1950] + [square of 1951 - square of 1952] + +[1997 square - 1998 square] + [1