Question

Aflati numerele naturale x si y,stiind ca sunt indeplinite simultan conditiile:x+y=120; x=3•y

Answer 1

x=3y
3y+y=120
4y=120
y=120:4
y=30
x=30x3=90

Answer 2

Inlocuim x cu 3y.
3y+y=120
4y=120
y=120:4
y=30
x=3 ori 30
x=90
90+30=120