Привет! Помогите°°°пожалуйста. Спасибо за ответ заранее!

4 5/12 - 1 1/2 : (2 1/6 + 8/15) * 1 4/5 = 3 5/12 1) 2 1/6 + 8/15 = 2 5/30 + 16/30 = 2 21/30 = 2 7/10 2) 1 1/2 : 2 7/10 = 3/2 : 27/10 = 3/2 * 10/27 = 1/1 * 5/9 = 5/9 3) 5/9 * 1 4/5 = 5/9 * 9/5 = 1 4) 4 5/12 - 1 = 4 5/12 - 12/12 = 3 17/12 - 12/12 = 3 5/12  3 6/7х - 7/9х + 4 4/63х = 3 54/63х - 49/63х + 4 4/63х = 7 9/63х = 7 1/7х 4 2/9у + 3 1/5у - 2у = 4 10/45у + 3 9/45у - 2у = 7 19/45у - 2у = 7 19/45у - 1 45/45у = 6 64/45у - 1 45/45у = 5 19/45у