2х + 5 = 24
2х = 24 - 5
2х = 19
х = 19 : 2
х = 9,5
х + х - 3 = 15
2х - 3 = 15
2х = 15 + 3
2х = 18
х = 18 : 2
х = 9
2х + 5 = 24
2х = 24 - 5
2х = 19
х = 19 : 2
х = 9,5
х + х - 3 = 15
2х - 3 = 15
2х = 15 + 3
2х = 18
х = 18 : 2
х = 9