Răspuns :
a+b=300 ; 300-(a-b)=260|-300
-> a-b= -40
a+b=300
______________ facem scadere
Termenii "a" se reduc si ramane 2b=300- -40 adica 300+40 -> 2b=340 -> b=170
Si de asemenea a=300-170= 130
a+b=300
300-(a-b)=260
notam a-b cu x
300-x=260
x=40
a+b=300
a-b=40
a=40+b
40+b+b=300
2b=260
b=130
a+b=300
a+130=300
a=300-130
a=170
300-(a-b)=260
notam a-b cu x
300-x=260
x=40
a+b=300
a-b=40
a=40+b
40+b+b=300
2b=260
b=130
a+b=300
a+130=300
a=300-130
a=170