Răspuns :
Răspuns:
x+y+y+z+x+z=25+120+105
2x+2y+2z=250
2(x+y+z)=250
x+y+z=250:2=125
z=125-25=100
x=125-120=5
y=125-105=20
x + y = 25
y + z = 120
x + z = 105
y + z + x + z = 120 + 105
y + 2 × z + x = 225
2 × z + ( x + y ) = 225
2 × z + 25 = 225
2 × z = 225 - 25
2 × z = 200
z = 200 : 2
z = 100
y = 120 - z
y = 120 - 100
y = 20
x = 25 - y
x = 25 - 20
x = 5