1)a+b+c=81
a/b=4
c/b=2 rest 4
a/b=4=.>a=4b
c/b=2 rest4 =>c-4/b=2=>c-4=2b =>c=2b+4
4b+b+2b+4=81
7b=81-4
7b=77
b=77/7
b=11
a=4x11
a=44
c=2x11+4
c=26
44+11+26=81
2)a+b+c=138
a= 2c
b=a/4-2
b=2c/4-2
b=c/2-2
b=c/2-4/2
b=c-4/2
2c+c-4/2+c=138
4c+c-4+2c totul supra2=138
7c-4=2x138
7c=276+4
7c=280
c=280/7
c=40
a=2x40
a=80
b=80/4-2
b=18
80+40+18=138
3)b=a/3
2a+3b=333
2a+3a/3=333
3a=333
a=333/3
a=111
b=111/3
b=37
2x111+3x37=333
222+111=333
4)a+b=184
a/2=b+14
b=a/2-14
a+a/2-14=184
2a+a-28/2=184
3a-28=184x2
3a-28=368
3a=368+28
3a=396
a=396/3
a=132
b=132/2-14
b=66-14
b=52
132+52=184