a)
A .______.
B .______. +2. } 978(A+B+C)
C .______.+4.
___________________________
A=? B=? C=?
1) A•3= 978 -(2+4)=
=978 -6=
=972
2)A= 972:3=324
3) B= 324+2=326
4) C= 326+2=328
Verificare: 324+326+328=978 ✅
b)
A.____.
B.____.+2. }1719 (A+B+C)
C.____.+4
__________________
A=? B=? C=?
1) 3•A = 1719-(2+4)=
= 1719- 6 =
=1713
2) A= 1713:3= 571
3) B = 571+2=573
4) C= 573+2=575
Verificare: 571+573+575=1719 ✅