Вроде память не подводит, вообщем вот.
(2 2/5x + 6 1/2) : 1 4/7 - 2 4/9 = 4 5/9
12/5:11/7x + 13/2:11/7 - 22/9 = 41/9
84/55x + 91/22 = 41/9 + 22/9
84/55x = 7 - 91/22
84/55x = 7 - 4 3/22
84/55x = 2 19/22
84/55x=63/22
x = 63/22:84/55 = 63/22*55/84
x = 105/56 = 15/8 = 1 7/8