If a,b,c,d are in H.P., then prove that `ab+bc+cd=3ad`.

If a,b,c.d be in H.P.then prove that ab+bc+cd=3ad

If a,b,c and d are in H.P.,then prove that (b+c+d)/a,(c+d+a)/b,(d+a+b)/c and (a+b+c)/d, are in A.P.

If a,b,c,d are in H.P., then ab+bc+cd is equal to

If a,b,c,d are in GP then show that (a-b+c)(b+c+d)=ab+bc+cd

If (a-b),(b-c),(c-a) are in G.P.then prove that (a+b+c)^(2)=3(ab+bc+ca)

If a,b,c are in G.P.then prove that (a^(2)+ab+b^(2))/(bc+ca+ab)=(b+a)/(c+b)

If a,b,c,d are in G.P.prove that: (ab-cd)/(b^(2)-c^(2))=(a+c)/(b)

If a,b,c,d are positive numbers such that a,b,c are in A.P. and b,c,d are in H.P., then : (A) ab=cd (B) ac=bd (C) ad=bc (D)none of these