Concept:When multiple ratios are equal, set them equal to a common variable k and solve using algebra.Explanation:Let b+ca​=c+ab​=a+bc​=k.Then a=k(b+c), b=k(c+a), and c=k(a+b).Add the three equations:a+b+c=k[(b+c)+(c+a)+(a+b)].a+b+c=k[2(a+b+c)].a+b+c=2k(a+b+c).Assuming a+b+cî€ =0, divide both sides by a+b+c:1=2k.So k=21​.(If a+b+c=0, the ratio would be −1, but under the standard exam condition a+b+cî€ =0, the value is 21​.)Answer:Each ratio is equal to 21​.