Răspuns:
a/b=2/3=>a=2b/3
a+b=10
inlocuim pe a in relatie
2b/3+³⁾b=³⁾10
2b+3b=30=>b=30:5=>b=6
a=2b/3=>a=2·6:3=>a=4
_____________
x/y=1/3=>y=3x
(4x-y)/(y-x)= inlocuim pe y
(4x-3x)/(3x-x)=x/2x=1/2
