If `-2,4,10,...` are in `A.P` then `s_(21)`=

Let S_(1) be the sum of the first n terms of the A.P 8,12,16,... and let S_(2) be the sum of the first n terms of the A.P 17,19,21,... assume n!=0 then S_(1)=S_(2) for

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:

Suppose (1)/(2)x, lx,+1l,lx-1l,1l are in A.P., then sum to 10 terms of the A.P. is

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

If x,1,z are in A.P. x,2,z are in G.P., show thast 1/x,1/4,1/z are in A.P.

If the first and last term of an A.P. are 18 and 82 respectively, then S_(25)=

If the first two terms of an A.P. Are -3 and 4, then what is the 21st term of this A.P. ?

in an A.PS_(4)=16,S_(6)=-48 (where S_(n) denotes the sum of first n term of A.P then S_(10) is equal to

Let S_(n) denote the sum of the first n terms of an A.P.. If S_(4)=16 and S_(6)=-48 , then (S_(10))/(-80) is equal to ____________.