2b+v+z = 11
2b-2b+v+z = 11-2b
v-v+z = 11-2b-v
z = 11-2b-v
3b+5v+5z = 34
3b+5v+5(11-2b-v) = 34
3b+5v+5(11) (5)(-2b) (5)(-v) = 34
3b+5v+55-10b-5v=34
55-7b=34
55-7b-55=34-55
-7b=-21
-7b/-7=-21/-7
b=3
v=4
z = 11-2(3)-4
z=11-6-4=1
z = 11-2b-v
5b+6v+3z = 42
5(3)+6v+3(11-2b-v) = 42
5(3)+6v+3(11) (3)(-2b) (3)(-v) = 42
15+6v+33-18-3v=42
15+3v+33-18=42
3v+30=42
3v+30-30=42-30
3v=12
3v/3=12/3
v=4