выполнить действия пожалуйста

(1/12 + 1/6) : (3/8 - 1/4) = (1+2)/12 : (3-2)/8 = 3/12 : 1/8 = 3/12 * 8/1 = 3/3 * 2/1 = 6/3 = 2
(1 - 4/9) : (1/3 - 1/4) = 5/9 : (4-3)/12 = 5/9 : 1/12 = 5/9 * 12/1 = 5/3 * 4/1 = 20/3 = 6 2/3