в)а=b a=b a=b a=b a=-3
2b+3b=-15 5b=-15 b=-15:5 b=-3 b=-3
2a+3b=-15
a=b
2a+3a=-15
5a=-15
a=-3
a=b=-3
m=-3n+6
-3n+6-2n-1=0
-5n+5=0
-5n=-5
n=1
m=-3+6=3
в)а=b a=b a=b a=b a=-3
2b+3b=-15 5b=-15 b=-15:5 b=-3 b=-3
2a+3b=-15
a=b
2a+3a=-15
5a=-15
a=-3
a=b=-3
m=-3n+6
-3n+6-2n-1=0
-5n+5=0
-5n=-5
n=1
m=-3+6=3