If `a_(1),a_(2),a_(3),...,a_(100)` are in A P such that `a_(1)+a_(3)+a_(4)+a_(3)+a_(7)=20` then `a_(4)=`

a_(1),a_(2),a_(3),......,a_(n), are in A.P such that a_(1)+a_(3)+a_(5)=-12 and a_(1)a_(2)a_(3)=8 then

a_(1),a_(2),a_(3)...,a_(n) are in A.P.such that a_(1)+a_(3)+a_(5)=-12 and a_(1)a_(2)a_(3)=8 then:

If a_(1),a_(2),a_(3),".....",a_(n) are in HP, than prove that a_(1)a_(2)+a_(2)a_(3)+a_(3)a_(4)+"....."+a_(n-1)a_(n)=(n-1)a_(1)a_(n)

If a_(1),a_(2),a_(3),a_(4),......... are in A.P. such that a_(1)+a_(5)+a_(10)+a_(15)+a_(20)+a_(24)=450 then a_(1)+a_(8)+a_(17)+a_(24)=

If a_(1), a_(2), a_(3),........, a_(n) ,... are in A.P. such that a_(4) - a_(7) + a_(10) = m , then the sum of first 13 terms of this A.P., is:

a_(1),a_(2),a_(3),a_(n) are in A.P.and a_(1)+a_(3)+a_(5)+a_(7)+a_(9)=20 then a_(5) is 2 .7 3.34.45.5

If a_(1),a_(2),a_(3),a_(4) are positive real numbers such that a_(1)+a_(2)+a_(3)+a_(4)=16 then find maximum value of (a_(1)+a_(2))(a_(3)+a_(4))

Three positives integers a_(1),a_(2),a_(3) are in A.P. , such that a_(1)+a_(2)+a_(3)= 33 and a_(1) xx a_(2) xx a_(3) = 1155 . Find the intergers a_(1),a_(2),a_(3) .

. If a_(1),a_(2),a_(3),...,a_(2n+1) are in AP then (a_(2n+1)+a_(1))+(a_(2n)+a_(2))+...+(a_(n+2)+a_(n)) is equal to