1) 6 * 1/3 * x - 3/4 = 7/8
2*x - 3/4 = 7/8
2*x = 7/8 + 3/4 // Домножаем 3/4 на 2
2*x = 13/8
x = 13/16
2) 1,8 * х/3,2 = 0,25/6
x/2 = 0,25/6
x = 1/12
3) 1*2/5 - х + 4/7 = 2,6/3
2/5 + 4/7 - 2,6/3 = x
(14 + 20)/35 - 2,6/3 = x
102/105 - 91/105 = x
11/105 = x
4) 2,7/х - 3 = 7,2/2 | *10
27/x - 30 = 72 / 2
27/x = 61
x = 61/27
x = 2 + 7/27