Răspuns :
Ma=(a+b+c)/3=37
c=3a+15
2a=b+12,b=2a-12
a+b+c=111
a+2a-12+3a+15=111
6a=111-15+12=108
a=108:6=18
b=2x18-12=36-12=24
c=3x18+15=54+15=69
18+24+69=11
c=3a+15
2a=b+12,b=2a-12
a+b+c=111
a+2a-12+3a+15=111
6a=111-15+12=108
a=108:6=18
b=2x18-12=36-12=24
c=3x18+15=54+15=69
18+24+69=11