If `a ,\ b ,\ c` are in proportion, then (a) `a : b :: b : c` (b) `a : b :: c : a` c) `a : b :: c : b` (d) `a : c :: b : c`

If a ,\ b ,\ c are in proportion, then (a) a^2=b c (b) b^2=a c (c) c^2=a b (d) None of these

If a ,\ b ,\ c ,\ d are in proportion, then (a) a b=c d (b) a c=b d (c) a d=b c (d) None of these

If a, b, c, d are in proportion, then a : b = c : d and written as a : b : : c : d . Which of the following is true?

If a,b,c are in continued proportion, then prove that (b/(b+c)=(a-b)/(a-c)

If (a + b + c + d) (a - b - c + d) = (a + b - c - d) (a - b + c - d) , prove that: a : b = c : d .

If a, b, c are in continued proportion, prove that (a+b+c)(a-b+c)=a^(2)+b^(2)+c^(2) .

If a, b, c, d are in continued proportion, then prove that (b -c)^(2) + (c -a)^(2) + (b-d)^(2) = (a -d)^(2)

(i) If a , b , c are in continued proportion, show that : (a^(2) + b^(2))/(b(a+c)) = (b(a + c))/(b^(2) + c^(2)) . (ii) If a , b , c are in continued proportion and a(b - c) = 2b , prove that : a - c = (2(a + b))/(a) . (iii) If (a)/(b) = (c)/(d) show that : (a^(3)c + ac^(3))/(b^(3)d +bd^(3)) = ((a + c)^(4))/((b + d)^(4)) .

If (b + c) (y + z) - ax = b - c, (c + a) (z + x) - by = c - a and (a + b) (x + y) - cz = a - b , where a + b + c ne 0, then x is equal to a) (c + b)/(a + b + c) b) (c - b)/(a + b + c) c) (a - b)/(a + b + c) d) (a + b)/(a + b + c)