d.
a=primul nr
b= al 2 lea nr
c= al 3 lea nr
a=b:7 (1)
b=c-123 (2)
Din 1 si 2=> a= (c-123):7
a+b+c=1623
(c-123):7 + c-123 +c =1623
(c-123):7+2c=1746
(c-123):7 + (14c):7=(12222):7 | •7
c-123 +14c=12222
15c=12345
c=823
b=823-123=700
c=700:7=100
f.
a=b:4
a=c:2
b=c+30
a=(c+30):4 (1)
a=c:2 (2)
Din (1) si (2)=>
(c+30):4=c:2
(c+30):4=2c:4 (am amplificat in partea dreapta) |•4
=>c+30=2c
c=30
b=30+30=60
a=60:4=15
