a) a+b+c=975
a/-----/..12..
b/-----/.......345......
c/-----/....126... } 975
975 - (12+345+126)=975 - 483=492 (suma a 3 segm egale)
492:3=164
a=164+12=176
b=164+345=509
c= 164+126=290
b) nr este 2a
2a-a=15
a=15
numarul=2*15=30
S+Z=12
daca e nr cel mai mare rezulta ca M=9
S-Z=2
2S=14 ⇒ S=14:2=7 ⇒ Z=5
Numarul este 9758
d) E=a
D=3*a
C=3a-40
B= 3a-40+25
B=3a-15
A=2*(3a-15)=6*a-30
suma B+C+D+E =815
3*a-15+3*a - 40+3*a+a=10*a-15-40=815
10*a=815+15+40=870
a=87
A=6*87-30=492
B=3*87-15=246
C=3*87 - 40= 221
D=3*87=261
E=87