Question

Aflati trei numere naturale x, y si z,stiind ca: x+y=56
y+z=88
x+z=80

Answer 1

x+y=56
y+z=88
x+z=80
x=? y=? z=?
2x+2y+2z=56+80+88
2x(x+y+z)=224
x+y+z=112
z=112-56
z=56
x=112-88
x=24
y=112-80
y=32

Answer 2

x+y=56⇒y=56-x
y+z=88
x+z=80⇒z=80-x
Inlocuim in a doua ecuatia si obtinem:
56-x+80-x=88
-2x+136=88
-2x=-48⇒x=24
y=56-x⇒y=32
z=80-x⇒z=56