Răspuns:
[tex]a+b+c=450\\\\c=\frac{a+b}{2} = > a+b=2c\\\\b-a=a/2= > 2(b-a)=a= > 2b-2a=a= > 2b=a+2a= > 2b=3a= > b=3a/2\\\\2c+c=450= > c=450:3= > c=150\\\\a+b=2*150= > a+b=300\\\\a+3a/2=300/*2\\\\2a+3a=600= > a=600:5= > a=120\\\\b=3*120:2= > b=180[/tex]