4/7x5/9, 3/5x5/12, 4x7/16, 5 5/8x1 5/9

[1] 4/7 • 5/9 = 20/63[2] 3/5 • 5/12 = 15/60[3] 4 • 7/16 4/1 • 7/16 = 28/16 или 1 12/16[4] 5 5/8 • 1 5/9 45/8 • 14/9 = 630/72 или 8 54/72