VI.3.205
p=penar
g=ghiozdan
6p+3g=111 (:3)
2p+3g=87
2p+g=37
2p+3g=87
(2p+3g)-(2p+g)=87-37
2p+3g-2p-g=50
2g=50
g=50:2
g=25 lei costa un ghiozdan
2p+25=37
2p=37-25
2p=12
p=12:2
p=6 lei costa un penar
VI.3.206
a+b+c=118
a=3b
b=c+7
a=b:3
c=b-7
3b+b+b-7=118
5b=118+7
5b=125
b=125:5
b=25
a=3x25=75
c=25-7=18
75+25+18=118
V.3.207
R+V+A=234
R=A:4
R=V+12
A=4R
V=R-12
R+R-12+4R=234
6R=234+12
6R=246
R=246:6
R=41 lei are Radu
A=4x41=164 lei are Andrei
V=41-12=29 lei are Valentin
VI.3.208
a+b+c=600
b=2a
c=3x2b=6b
a=b:2
b:2+b+6b=600
b:2+7b=600 (x2)
b+14b=1200
15b=1200
b=1200:15
b=80
a=80:2=40
c=6x80=480
a+b+c=600
40+80+480=600