4,5 : х + 3/4 = 2 19/28
4,5 : х = 2 19/28 - 3/4
4,5 : х = 2 19/28 - 21/28
4,5 : х = 1 47/28 - 21/28
4,5 : х = 1 26/28 = 1 13/14
х = 45/10 : 1 13/14 = 45/10 : 27/14
х = 45/10 * 14/27
х = 35/15 = 7/3
х = 2 1/3
Проверка: 45/10 : 7/3 = 2 19/28 - 3/4
45/10 * 3/7 = 1 47/28 - 21/28
135/70 = 1 26/28
1 65/70 = 1 13/14
1 13/14 = 1 13/14