Răspuns :
p+s=5
s+c=7
p+c=6
2p+2s+2c=5+7+6
2(p+s+c)=18
p+s+c=9
c=9-4
c=5 lei
p=9-7
p=2 lei
s=9-6
s=3 lei
s+c=7
p+c=6
2p+2s+2c=5+7+6
2(p+s+c)=18
p+s+c=9
c=9-4
c=5 lei
p=9-7
p=2 lei
s=9-6
s=3 lei
pixul=a
stiloul=b
caietul=c
a+b=5
b+c=7
a+c=6
c=6-a
b+6-a=7
b=7-6+a
b=a+1
a+a+1=5
2a=4
a=2
2+b=5
b=3
2+c=6
c=4
stiloul=b
caietul=c
a+b=5
b+c=7
a+c=6
c=6-a
b+6-a=7
b=7-6+a
b=a+1
a+a+1=5
2a=4
a=2
2+b=5
b=3
2+c=6
c=4