Question

Ana are cu 25 de lei mai mult decât Barbu si cu 15 lei mai
putin decât Catlin. Împreuna  au 395 de lei. Câti lei are fiecare?

Answer 1

A+B+C=395
A=B+25=>B=A-25
A=C-15=>C=A+15
A+A-25+A+15=395
3A=395+25-15
A=405:3
A=135 lei are Ana
B=135-25=110 lei are Barbu
C=135+15=150 lei are Catalin

Answer 2

|-----| Barbu
|-----| +25 Ana
|-----|+25+15 Catalin
B+A+C=395
25+25+15=65
395-65=330
330:3=110 are Barbu
110+25=135 are Ana
110+25+15=150 are Catalin
110+135+150=395(verificare)