coollimit

Verified answer

3ах+х=12
х(3а+1)=12
х=-9
-9*(3а+1)=12
3а+1=12/(-9)
3а=-7/3
а=-7/3*1/3
а=-7/9


2. х=2
(5а+2)*2=8-2а
10а+4=8-2а
12а=4
а=4/12
а=1/3