Răspuns :
(2a+1)*3 +2=65
(2a+1)*3=65-2
(2a+1)*3=63
2a+1=63:3
2a+1=21
2a=21-1
2a=20
a=20:2
a=10
(2a+1)*3=65-2
(2a+1)*3=63
2a+1=63:3
2a+1=21
2a=21-1
2a=20
a=20:2
a=10
Sper ca este correct
a·2+1=b
b·3+2=c
65:5=13
13-(1+2)=10 nr cautat
verificare: 10·2+1=21
21·3+2=65