найдиие значения вырожений (19-15 4/7)÷16/21+6 3/5 - 4 5/6

1) 19 - 15 4/7 = 3 3/72) 3 3/7 ÷ 16/21 = 24/7 ÷ 16/21 = 24/7 * 21/16 = 9/2 = 4 1/23) 4 1/2 + 6 3/5 = 4 5/10 + 6 6/10 = 11 1/104) 11 1/10 - 4 5/6 = 11 3/30 - 4 25/30 = 6 8/30 = 6 4/15