(k+5)*7-54=(k+5)*4
7k+35-4k-20=54
3k+15=54
3k=54-15
3k=39
k=39:3
к=13
7k+35-54=4k+20
7k-4k=54-35+20
k=39/3
k=13
(k+5)*7-54=(k+5)*4
7k+35-4k-20=54
3k+15=54
3k=54-15
3k=39
k=39:3
к=13
(k+5)*7-54=(k+5)*4
7k+35-54=4k+20
7k-4k=54-35+20
3k=39
k=39/3
k=13