Question

3.1.25
Даю 39 б......

Answer 1

у=11+2х
3(х-1)+ 2у=12

3х-3+2у=12
у=11+2х

3х+2у=15
у=11+2х

3х+2(11+2х)=15
3х+22+4х=15
7х=-7
х=-1

у=11+ 2*(-1)
у=9