В) 3/5 : (9/10 – 3/5 ·8/9) = 1 цел 7/11
1) 3/5 · 8/9 = 1/5 ·8/3 = 8/15 2) 9/10 – 8/15 = (3·9–2·8)/30 = (27–16)/30 = 11/30
3) 3/5 : 11/30 = 3/5 · 30/11 = 90/55 = 18/11 = 1 цел 7/11
а) 4 · 1/5 + 4 · 3/7 – 4 · 1/35 = 4·(1/5 +3/7–1/35) = 4·(7+15–1)/35 =
= 4·21/35 = 4·3/5 =12/5 = 2,4
в) 3/2 · 5/6 + 3/2 : 9/10 – 3/2 · 13/18 = 3/2 · 5/6 + 3/2 · 10/9 – 3/2 · 13/18 =
= 3/2·(5/6 + 10/9 – 13/18) = 3/2 · (15/18 + 20/18 – 13/18) = 3/2 · 22/18 =
= 11/6 = 1 цел 5/6