а) 1 4/9 · 9 = (1 + 4/9) · 9 = 1 · 9 + 4/9 · 9 = 9 + 4 = 13
б) (5/14 + 1 1/7) · 7 = (5/14 + 8/7) · 7 = 5/14 · 7 + 8/7 · 7 = 5/2 + 8 = 2 1/2 + 8 = 10 1/2
в) 4 3/5 · 4/9 + 4/9 · 4 2/5 = 4/9 · (4 3/5 + 4 2/5) = 4/9 · 9 = 4
а) 1 4/9 · 9 = (1 + 4/9) · 9 = 1 · 9 + 4/9 · 9 = 9 + 4 = 13
б) (5/14 + 1 1/7) · 7 = (5/14 + 8/7) · 7 = 5/14 · 7 + 8/7 · 7 = 5/2 + 8 = 2 1/2 + 8 = 10 1/2
в) 4 3/5 · 4/9 + 4/9 · 4 2/5 = 4/9 · (4 3/5 + 4 2/5) = 4/9 · 9 = 4