1) (х+0.75)+(х+0.8)=5.4
2х+1,55=5.4
2х=5.4-1.55
2х=3.85
х=3.85/2
х=1.925
2) 1.925+0.8=2.725
3) 1.925+0.75=2.720
Проверка: 2.720+2.725 ~ 5.4
1) (х+0.75)+(х+0.8)=5.4
2х+1,55=5.4
2х=5.4-1.55
2х=3.85
х=3.85/2
х=1.925
2) 1.925+0.8=2.725
3) 1.925+0.75=2.720
Проверка: 2.720+2.725 ~ 5.4