Question

gaseste numerele x,y.zstiind ca x+y+z=7000 y+x=4280 y=x+520

Answer 1

x+y+z=7 000
x+y=4 280
y=x+520

x+x+520=4 280
2x=4 280-520
x=3 760:2
x=1 880
y=1 880+520=>y=2 400
4 280+z=7 000
z=7 000-4 280
z=2 720
Proba:1 880+2 400+2 720=7 000