2(х-4)-(х-1)=30
2х-8-(х-1)=30
2х-8-х+1=30
х-7=30
х=30+7
х=37.
2(x-4)-(x-1)=30
х=37
2(37-4)-(37-1)=30
66-36=30
30=30
2(х-4)-(х-1)=30
2х-8-(х-1)=30
2х-8-х+1=30
х-7=30
х=30+7
х=37.
2(x-4)-(x-1)=30
2х-8-х+1=30
х-7=30
х=30+7
х=37
2(37-4)-(37-1)=30
66-36=30
30=30