Помогите: (5/6 - 3/8):3/4 - (3/8 + 7/20): одну целую 9/20 Ответ: 1/9 мне нужно решение, плиз

(5/6 - 3/8) : 3/4 - (3/8 + 7/20) : 1 цел. 9/20 = 1/9 1) 5/6 - 3/8 = 20/24 - 9/24 = 11/24  2) 11/24 : 3/4 = 11/24 * 4/3 = (11*1)/(6*3) = 11/18 3) 3/8 + 7/20 = 15/40 + 14/40 = 29/40 4) 29/40 : 1 цел. 9/20 = 29/40 : 29/20 = 29/40 * 20/29 = 20/40 = 1/2 5) 11/18 - 1/2 = 11/18 - 9/18 = 2/18 = 1/9