Question :- 

If (a+b)/(b+c) = (c+d)/(d+a), then
 

a) a = c                            b) either a = c or a + b + c + d = 0
c) a + b + c + d = 0          d) a = c and b = d


(a+b)/(b+c) = (c+d)/(d+a) = k(say) • (a+b) + (c+d) = k(b+c) + k(d+a) or (k - 1)(a + b + c + d) = 0 • Either a + b + c +d = 0 or k = 1 ⇒ a + b = b = b +c ⇒ a = c
 

Ans: b) either a = c or a + b + c + d = 0