2 1/2х - 1 5/8 = 2 3/4
2 1/2х = 2 3/4 + 1 5/8
2 1/2х = 2 6/8 + 1 5/8
2 1/2х = 3 11/8 = 4 3/8
х = 4 3/8 : 2 1/2
х = 35/8 : 5/2
х = 35/8 * 2/5
х = 7/4 = 1 3/4
1 1/2х + 1/2х = 1 2/3
1 2/2х = 1 2/3
2х = 1 2/3
х = 1 2/3 : 2
х = 5/3 : 2/1
х = 5/3 * 1/2
х = 5/6