Răspuns :
Notam:
x+y=804
x-y=146
x=146+y
146+y+y=804
146+2y=804
2y=804-146
2y=658
y=329
x+y=804
x+329=804
x=804-329
x=475
x+y=804
x-y=146
x=146+y
146+y+y=804
146+2y=804
2y=804-146
2y=658
y=329
x+y=804
x+329=804
x=804-329
x=475