-6d-25=-79 | *-1
6d+25=79
6d=79-25
6d=54
d=9
0,7c-2,5=4,5
0,7c=4,5+2,5
0,7c=7
c=10
-9m-1=-29-2m | *-1
9m+1=29+2m
9m-2m=29-1
7m=28
m=4
4(d-7)+28=36
4d-28+28=36
4d=36
-6d-25=-79 | *-1
6d+25=79
6d=79-25
6d=54
d=9
0,7c-2,5=4,5
0,7c=4,5+2,5
0,7c=7
c=10
-9m-1=-29-2m | *-1
9m+1=29+2m
9m-2m=29-1
7m=28
m=4
4(d-7)+28=36
4d-28+28=36
4d=36
d=9