4)
ian /-------/
feb /-------/ +35
mar /--------/ +35 -17
total 893
3segm+35+35-17=893
3segm=893-70+17=840
1segm=840:3=280
ian=280
feb=280+35=315
mar=315-17=298
proba: 280+315+298=893
5)
se rezolva de jos in sus, am inceput cu d, apoi c, b si a :
ax2=b ax2=210 a=210:2=105 a=105
b:3=c b:3=70 b=70x3=210 b=210
c+36=d c+36=106, c=106-36=70 c=70
d-19=87 d=87+19=106 d=106
a-304=b a-304=167, a=167+304=638 a=638
b+29=c b+29=196, b=196-29=167 b=167
c:4=d c:4=49, c=4x49=196 c=196
dx6=294 d=294:6=49 d=49
a+b=300 a+288=300 a=12
b=cx9 b=32x9 b=288
c=d+13 c=19+13=32 c=32
d=e:6 d=114:6=19 d=19
e:6=19 e=6x19=114 e=114
axb=90 ax90=90 a=1
b=cx3 b=30x3=90 b=90
c=d:10 c=300:10=30 c=30
d-e=250 d-50=250 d=300
e:10=5 e=10x5=50 e=50
