Пошаговое объяснение:
3/4+1/3=13/12
3/4-1/3=5/12
5/12*13/12=65/144
(3/4 + 1/3) * (3/4 - 1/3) =
(9/12 + 4/12) * (9/12 - 4/12) =
13/12 * 5/12 = 65/144
